Part ii

., p. 235-248.

The air which Martins collected at Faulhorn at an elevation of 8767 feet, contained as much oxygen as the air at Paris.*

[footnote] *Dumas, in the 'Annales de Chimie, 3e Serie', t. iii., 1841, p. 257.

The admixture of carbonate of ammonia in the atmosphere may probably be considered as older than the existence of organic beings on the surface of the earth. The sources from which carbonic acid* may be yielded to the atmosphere are most numerous.

[footnote] *In this enumeration, the exhalation of carbonic acid by plants during the night, while they inhale oxygen, is not taken into account, because the increase of carbonic acid from this source is amply counter-balanced by the respiratory process of plants during the day. See Boussingault's 'Econ. Rurale', t. i., p. 53-68, and Liebig's 'Organische Chemie', s. 16, 21.

In the first place we would mention the respiration of animals, who receive the carbon which they inhale from vegetable food, while vegetables receive it from the atmosphere; in the next place, carbon is supplied from the interior of the earth in the vicinity of exhausted volcanoes and thermal springs, from the decomposition of a small quantity of carbureted hydrogen gas in the atmosphere, and from the electric discharges of clouds, which are of such frequent occurrence within the tropics. Besides these substances, which we have considered as appertaining to the atmosphere at all heights that are accessible to us, there are others accidentally mixed with them, especially near the ground, which sometimes, in the form of miasmatic and gaseous contagia, exercise a noxious influence on animal organization. Their chemical nature has not yet been ascertained by direct analysis; but, from the consideration of the processes of decay which are perpetually going on in the animal and vegetable substances with which the surface of our planet is covered, and judging from analogies deduced from the comain of pathology, we are led to infer the existence of such noxious local admixtures. Ammoniacal and other nitrogenous vapors, sulphureted hydrogen gas, and compounds analogous to the polybasic ternary and quaternary compounds analogous to the polybasic ternary and quaternary combinations of the vegetable kingdom, may produce miasmata,* p 313 which, under various forms, may generate ague and typhus fever (not by any means exclusively on wet, marshy ground, or on coasts covered by putrescent mollusca, and low bushes of 'Rhizophora mangle' and Avicennia).

[footnote] *Gay-Lussac, in 'Annales de Chimie', t. liii., p. 120; Payen, Mem. sur la Composition Chimique des Vegetaux, p. 36, 42; Liebig, 'Org. Chemie', s. 229-345; Boussingault, 'Econ. Rurale', t. i., p. 142-153.

Fogs which have a peculiar smell at some seasons of the year, remind us of these accidental admixtures in the lower strata of the atmosphere. Winds and currents of air caused by the heating of the ground even carry up to a considerable elevation solid substances reduced to a fine powder. The dust which darkens the air for an extended area, and falls on the Cape Verd Islands, to which Darwin has drawn attention, contains, according to Ehrenberg's discovery, a host of silicious-shelled infusoria.

As principal features of a general descriptive picture of the atmosphere, we may enumerate:

1. 'Variations of atmospheric pressure': to which belong the horary oscillations, occurring with such regularity in the tropics, where they produce a kind of ebb and flow in the atmosphere, which can not be ascribed to the attraction of the moon,* and which differs so considerably according to geographical latitude, the seasons of the year, and the elevation above the level of the sea.

[footnote] *Bouvard, by the application of the formulae, in 1827, which Laplace had deposited with the Board of Longitude shortly before his death, found that the portion of the horary oscillations of the pressure of the atmosphere, which depends on the attraction of the moon, can not raise the mercury in the barometer at Paris more than the 0.018 of a millimeter, while eleven years' observations at the same place show the mean barometric oscillation, from 9 A.M. to 3 P.M., to be 0.756 millim., and from 3 P.M. to 9 P.M., 0.373 millim. See 'Memoires de l'Acad. des Sciences', t. vii., 1827, p. 267.

2. 'Climatic distribution of heat', which depends on the relative position of the transparent and opaque masses (the fluid and solid parts of the surface of the earth), and on the hypsometrical configuration of continents; relations which determine the geographical position and curvature of the isothermal lines (or curves of equal mean annual temperature) both in a horizontal and vertical direction, or on a uniform plane, or in different superposed strata of air.

3. 'The distribution of the humidity of the atmosphere'. The quantitative relations of the humitidy depend on the differences in the solid and oceanic surfaces; on the distance from the equator and the level of the sea; on the form in which the p 314 aqueous vapor is precipitated, and on the connection existing between these deposits and the changes of temperature, and the direction and succession of winds.

4. 'The electric condition of the atmosphere'. the primary cause of this condition, when the heavens are serene, is still much contested. Under this head we must consider the relation of ascending vapors to the electric charge and the form of the clouds, according to the different periods of the day and year; the difference between the cold and warm zones of the earth, or low and high lands; the frequency or rarity of thunder storms, their periodicity and formation in summer and winter; the causal connection of electricity, with the infrequent occurrence of hail in the night, and with the phenomena of water and sand spouts, so ably investigated by Peltier.

The horary oscillations of the barometer, which in the tropics present two maxima (viz., at 9 or 9 1/4 P.M., and 4 A.M., occurring, therefore, in almost the hottest and coldest hours), have long been the object of my most careful diurnal and nocturnal observations.*

[footnote] *'Observations faites pour constater la Marche des Variations Horaires du Barometre sous les Tropiques', in my 'Relation Historique du Voyage aux Regions Equinoxiales', t. iii., p. 270-313.

Their regularity is so great, that, in the daytime especially, the hour may be ascertained from the height of the mercurial column without an error, on the average, of more than fifteen or seventeen minutes. In the torrid zones of the New Continent, on the coasts as well as at elevations of nearly 13,000 feet above the level of the sea, where the mean temperature falls to 44.6 degrees, I have found the regularity of the ebb and flow of the aerial ocean undisturbed by storms, hurricanes, rain, and earthquakes. The amount of the daily oscillations diminishes from 1.32 to 0.18 French lines from the equator to 70 degrees north latitude, where Bravais made very accurate observations at Bosekop.*

[footnote] *Bravais, in Daemtz and Martins, 'Meteorologie', p. 263. At Halle (51 degrees 29' N. lat.), the oscillation still amounts to 0.28 lines. It would seem that a great many observations will be required in order to obtain results that can be trusted in regard to the hours of the maximum and minimum on mountains in the temperate zone. See the observations of horary variations, collected on the Faulhorn in 1832, 1841, and 1842 (Martins, 'Meteorologie', p. 254.)

The supposition that, much nearer the pole, the height of the barometer is really less at 10 A.M. than at 4 P.M., and consequently, that the maximum and minimum influences of these hours p 315 are inverted, is not confirmed by Parry's observations at Port Bowen (73 degrees 14').

The mean height of the barometer is somewhat less under the equator and in the tropics, owing to the effect of the rising current,* than in the temperate zones, and it appears to attain its maximum in Western Europe between the parallels of 40 degrees and 45 degrees.

[footnote] *Humboldt, 'Essai sur la Geographie des Plantes', 1807, p. 90; and in 'Rel. Hist.', t. iii., p. 313; and on the diminuation of atmospheric pressure in the tropical portions of the Atlantic, in Poggend., 'Annalen der Physik', bd. xxxvii., s. 245-258, and s. 463-486.

If with Kämtz we connect together by 'isobarometric' lines those places which present the same mean difference between the monthly extremes of the barometer, we shall have curves whose geographical position and inflections yield important conclusions regarding the influence exercised by the form of the land and the distribution of seas on the oscillations of the atmosphere. Hindostan with its high mountain chains and triangular peninsulas, and the eastern coasts of the New Continent, where the warm Gulf Stream turns to the east at the Newfoundland Banks, exhibit greater isobarometric oscillations than do the group of the Antilles and Western Europe. The prevailing winds exercise a principal influence on the diminution of the pressure of the atmosphere, and this, as we have already mentioned, is accompanied, according to Daussey, by an elevation of the mean level of the sea.•

[footnote] *Dausay, in the 'Comptes Rendus', t. iii., p. 136.

As the most important fluctuations of the pressure of the atmosphere, whether occurring with horary or annual regularity, or accidentally, and then often attended by violence and danger,* are like all the other phenomena of the weather, mainly owing to the heating force of the sun's rays, it has long been suggested (partly according to the idea of Lambert) that the direction of the wind should be compared with the height of the barometer, alternations of temperature, and the increase and decrease of humidity.

[footnote] *Dove, 'Ueber die Sturme', in Poggend., 'Annalen', bd. lii., s. 1.

Tables of atmospheric pressure during different winds, termed 'barometric windroses', afford a deeper insight into the connection of meteorological phenomena.*

[footnote] *Leopold von Buch, 'Barometrische Windrose', in 'Abhandl. der Akad. der Wiss. zu Berlin aus den Jahren', 1818-1819, s. 187.

Dove has, with admirable sagacity, recognized, in the "law of rotation" in both hemispheres, which he himself established, the cause of many important processes in the aerial ocean.*

[footnote] *See Dove, 'Meteorologishe Untersuchungen', 1837, s. 99-313; and the excellent observations of Kämtz on the descent of the west wind of the upper current in high latitudes, and the general phenomena of the direction of the wind, in his 'Vorlesungen uber µeterologie', 1840, s. 58-66, 196-200, 327-336, 353-364; and in Schumacher's 'Jahrbuch fur' 1838, s. 291-302. A very satisfactory and vivid representation of meteorological phenomena is given by Dove, in his small work entitled 'Witterungsverhältnisse von Berlin', 1842. On the knowledge of the earlier navigators of the rotation of the wind, see Churruca, 'Viage at Magellanes', 1793, p. 15; and on a remarkable expression of Columbus, which his son Don Fernando Colon has presented to us in his 'Vida del Almirante', cap. 55, see Humboldt, 'Examen Critique de l'Hist. de Geographie', t. iv., p. 253.

The difference of temperature between the p 315 equatorial and polar regions engenders two opposite currents in the upper strata of the atmosphere and on the Earth's surface. Owing to the difference between the rotatory velocity at the poles and at the equator, the polar current is deflected eastward, and the equatorial current westward. The great phenomena of atmospheric pressure, the warming and cooling of the strata of air, the aqueous deposits, and even, as Dove has correctly represented, the formation and appearance of clouds, alike depend on the opposition of these two currents, on the place where the upper one descends, and on the displacement of the one by the other. Thus the figures of the clouds, which form an animated part of the charms of a landscape, announce the processes at work in the upper regions of the atmosphere, and, when the air is calm, the clouds will often present, on a bright summer sky, the "projected image" of the radiating soil below.

Where this influence of radiation is modified by the relative position of large continental and oceanic surfaces, as between the eastern shore of Africa and the western part of the Indian peninsula, its effects are manifested in the Indian monsoons, which change with the periodic variations in the sun's declination,* and which were known to the Greek navigators under the name of 'Hippalos'.

[footnote] *'Monsun' (Malayan 'musim', the 'hippalos' of the Greeks) is derived from the Arabic word 'mausim', a set time or season of the year, the time of the assemblage of pilgrims at Mecca. The word has been applied to the seasons at which certain winds prevail, which are, besides, named from places lying in the direction from whence they come; thus, for instance, there is the 'mausim' of Aden, of Guzerat, Malabar, etc. (Lassen, 'Indische Alterthumskunde', bd. i., 1843, s. 211). On the contrasts between the solid or fluid substrata of the atmosphere, see Dove, in 'Der Abhandl. der Akad. der Wiss. zu Berlin aus dem Jahr' 1842, s. 239.

In the knowledge of the monsoons, which undoubtedly dates back thousands of years among the inhabitants of Hindostan and China, of the eastern parts of the Arabian Gulf and of the western shores of the Malayan p 317 Sea, and in the still more ancient and more general acquaintance with land and sea winds, lies concealed, as it were, the germ of that meteorological sciences which is now making such rapid progress. The long chain of 'magnetic stations' extending from Moscow to Pekin, across the whole of Northern Asia, will prove of immense importance in determining the 'law of the winds', since these stations have also for their object the investigation of general meteorological relations. The comparison of observations made at places lying so many hundred miles apart, will decide, for instance, whether the same east wind blows from the elevated desert of Gobi to the interior of Russia, or whether the direction of the Aerial current first began in the middle of the series of the stations, by the descent of the air from the higher regions. By means of such observations, we may learn, in the strictest sense, 'whence' the wind cometh. If we only take the results on which we may depend from those places in which the observations on the direction of the winds have been continued more than twenty years, we shall find (from the most recent and careful calculations of Wilhelm Mahlmann) that in the middle latitudes of the temperate zone, in both continents, the prevailing aerial current has a west-southwest direction.

Our insight into the 'distribution of heat' in the atmosphere has been rendered more clear since the attempt has been made to connect together by lines those places where the mean annual summer and winter temperatures have been ascertain by correct observations. The system of 'isothermal, osotheral' and 'isochimenal' lines, which I first brought into use in 1817, may, perhaps, if it be gradually perfected by the united efforts of investigators, serve as one of the main foundations of 'comparative climatology'. Terrestrial magnetism did not acquire a right to be regarded as a science until partial results were graphically connected in a system of lines of 'equal declination, equal inclinatiion', and 'equal intensity'.

The term 'climate', taken in its most general sense, indicated all the changes in the atmosphere which sensibly affect our organs, as temperature, humidity, variations in the barometrical pressure, the calm state of the air or the action of opposite winds, the amount of electric tension, the purity of the atmosphere or its admixture with more or less noxious gaseous exhalations, and, finally, the degree of ordinary transparency and clearness of the sky, which is not only important with respect to the increased radiation from the Earth, the organic development of plants, and the ripening of fruits, but p 318 also with reference to its influence on the feelings and mental condition of men.

If the surface of the Earth consisted of one and the same homogeneous fluid mass, or of strata of rock having the same color, density, smoothness, and power of absorbing heat from the solar rays, and of radiating it in a similar manner through the atmosphere, the isothermal, isotheral, and isochimenal lines would all be parallel to the equator. In this hypothetical condition of the Earth's surface, the power of absorbing and emitting light and heat would every where be the same under the same latitudes. The mathematical consideration of climate, which does not exclude the supposition of the existence of currents of heat in the interior, or in the external crust of the earth, nor of the propagation of heat by atmospheric currents, proceeds from this mean, and, as it were, primitive condition. Whatever alters the capacity for absorption and radiation, at places lying under the same parallel of latitude, gives rise to inflections in the isothermal lines. The nature of these inflections, the angles at which the isothermal, isotheral, or isochimenal lines intersect the parallels of latitude, their convexity or concavity with respect to the pole of the same hemisphere, are dependent on causes which more or less modify the temperature under different degrees of longitude.

The progress of 'Climatology' has been remarkably favored by the extension of European civilization to two opposite coasts, by its transmission from our western shores to a continent which is bounded on the east by the Atlantic Ocean. When, after the ephemeral colonization from Iceland and Greenland, the British laid the foundation of the first permanent settlements on the shores of the United States of America, the emigrants (whose numbers were rapidly increased in consequence either of religious persecution, fanaticism, or love of freedom, and who soon spread over the vast extent of territory lying between the Carolinas, Virginia, and the St. Lawrence) were astonished to find themselves exposed to an intensity of winter cold far exceeding that which prevailed in Italy, France, and Scotland, situated in corresponding parallels of latitude. But, however much a consideration of these climatic relations may have awakened attention, it was not attended by any practical results until it could be based on the numerical data of 'mean annual temperature'. If, between 58 degrees and 30 degrees north latitude, we compair Nain, on the coast of Labrador, with Gottenburg; Halifax with Bordeaus; New p 319 York with Naples; St. Augustine, in Florida, with Cairo, we find that, under the same degrees of latitude, the differences of the mean annual temperature between Eastern America and Western Europe, proceeding from north to south, are successively 20.7 degrees, 13.9 degrees, 6.8 degrees, and almost 0 degrees. The gradual decrease of the differences in this series extending over 28 degrees of latitude is very striking. Further to the south, under the tropics, the isothermal lines are every where parallel to the equator in both hemispheres. We see, from the above examples, that the questions often asked in society, how many degrees America (without distinguishing between the eastern and western shores) is colder than Europe? and how much the mean annual temperature of Canada and the United States is lower than that of corresponding latitudes in Europe? are, when thus 'generally expressed', devoid of meaning. There is a separate difference for each parallel of latitude, and without a special comparison of the winter and summer temperatures of the opposite coasts, it will be impossible to arrive at a correct idea of climatic relations, in their influence on agriculture and other industrial pursuits, or on the individual comfort or discomfort of manking in general.

In enumerating the causes which produce disturbances in the form of the isothermal lines, I would distinguish between those which 'raise' and those which 'lower' the temperature. To the first class belong the proximity of a western coast in the temperate zone; the divided configuration of a continent into peninsulas, with deeply-indented bays and inland seas; the aspect of the position of a portion of the land with reference either to a sea of ice spreading far into the polar circle, or to a mass of continental land of considerable extent, lying in the same meridian, either under the equator, or, at least, within a portion of the tropical zone; the prevalence of southerly or westerly winds on the western shore of a continent in the temperate northern zone; chains of mountains acting as protecting salls against the winds coming from colder regions; the infrequency of swamps, which, in the spring and beginning of summer, long remain covered with ice, and the absence of woods in a dry, sandy soil; finally the constant serenity of the sky in the summer months, and the vicinity of an oceanic current, bringing water which is of a higher temperature than that of the surrounding sea.

Among the causes which tend to 'lower' the mean annual temperature I include the following: elevation above the level of the sea, when not forming part of an extended plain; the p 320 vicinity of an eastern coast in high and middle latitudes; the compact configuration of a continent having no littoral curvatures or bays; the extension of land toward the poles into the region of perpetual ice, without the intervention of a sea remaining open in the winter; a geographical position, in which the equatorial and tropical regions are occupied by the sea, and consequently, the absence, under the same meridian, of a continental tropical land having a strong capacity for the absorption and radiation of heat; mountain chains, whose mural form and direction impede the access of warm winds, the vicinity of isolated peaks, occasioning the descent of cold currents of air down their declivities; extensive woods, which hinder the isolation of the soil by the vital activity of their foliage, which produces great evaporation, owing to the extension of these organs, and increases the surface that is cooled by radiation, acting consequently in a three-fold manner, by shade, evaporation, and radiation; the frequency of swamps or marshes, which in the north form a kind of subterranean glacier in the plains, lasting till the middle of the summer; a cloudy summer sky, which weakens the action of the solar rays; and, finally, a very clear winter sky, favoring the radiation of heat.*

[footnote] *Humboldt, 'Recherches sur les Causes des Inflexions des Lignes Isothermes', in 'Asie Centr.', t. iii., p. 103-114, 118, 122, 188.

The simultaneous action of these disturbing causes, whether productive of an increase or decrease of heat, determines, as the total effect, the inflection of the isothermal lines, especially with relation to the expansion and configuration of solid continental masses, as compared with the liquid oceanic. These perturbations give rise to convex and concave summits of the isothermal curves. There are, however, different orders of disturbing causes, and each one must, therefore, be considered separately, in order that their total effect may afterward be investigated with reference to the motion (direction, local curvature) of the isothermal lines, and the actions by which they are connected together, modified, destroyed, or increased in intensity, as manifested in the contact and intersection of small oscillatory movements. Such is the method by which, I hope, it may some day be possible to connect together, by empirical and numerically expressed laws, vast series of apparently isolated facts, and to exhibit the mutual dependence which must necessarily exist among them.

The trade winds -- easterly winds blowing within the tropics -- give rise, in both temperate zones, to the west, or west-southwest p 321 sinds which prevail in those regions, and which are land winds to eastern coasts, and sea winds to western coasts, estending over a space which, from the great mass and the sinking of its cooled particles, is not capable of any considerable degree of cooling, and hence it follows that the east winds of the Continent must be cooler than the west winds, where their temperature is not affected by the occurrence of oceanic currents near the shore. Cook's young companion on his second voyage of circumnavigation, the intelligent George Forster, to whom I am indebted for the lively interest which prompted me to undertake distant travels, was the first who drew attention, in a definite manner, to the climatic differences of temperature existing in the eastern and western coasts of both continents, and to the similarity of temperature of the western coast of North America in the middle latitudes, with that of Western Europe.*

[footnote] *George Forster, 'Klein Schriften', th. iii., 1794, s. 87; Dove, in Schumacher's 'Jahrbuch fur', s. 289; Kämtz, 'Meteorologie', bd. ii., s. 41, 43, 67, and 96; Arago, in the 'Comptes Rendus', t. i., p. 268.

Even in northern latitudes exact observations show a striking difference between the 'mean annual temperature' of the east and west coasts of America. The mean annual temperature of Nain, in (lat. 57 degrees 10'), is fully 6.8 degrees 'below' the freezing point, while on the northwest coast, at New Archangel, in Russian America (lat. 57 degrees 3'), it is 12.4 degrees 'above' this point. At the first-named place, the mean summer temperature hardly amounts to 43 degrees, while at the latter place it is 57 degrees. Pekin (39 degrees 54'), on the eastern coast of Asia, has a mean annual tempeerature of 52.8 degrees, which is 9 degrees below that of Naples, situated somewhat further to the north. The mean winter temperature of Pekin is at least 5.4 degrees below the freezing point, while in Western Europe, even at Paris (48 degrees 50'), it is nearly 6 degrees above the freezing point. Pekin has also a mean winter cold which is 4.5 degrees lower than that of Copenhagen, lying 17 degrees further to the north.

We have already seen the slowness with which the great mass of the ocean follows the variations of temperature in the atmosphere, and how the sea acts in equalizing temperatures, moderating simultaneously the severity of winter and the heat of summer. Hence arises a second more important contrast -- that, namely, between insular and littoral climates enjoyed by all articulated continents having deeply indented bays and peninsulas, and between the climate of the interior of great masses of solid land. This remarkable contrast has been fully p 322 developed by Leopold von Buch in all its various phenomena, both with respect to its influence on vegetation and agriculrure, on the transparency of the atmosphere, the radiation of the soil, and the elevation of the line of perpetual snow. In the interior of the Asiatic Continent, Tobolsk, Barnaul on the Oby, and Irkutsk, have the same mean summer heat as Berlin, Munster, and Cherbourg in Normandy, the thermometer sometimes remaining for weeks together at 86 degrees or 88 degrees, while the mean winter temperature is, during the coldest month, as low as -0.4 degrees to -4 degrees. These continental climates have therefore justly been termed 'excessive' by the great mathematician and physicist Buffon; and the inhabitants who live in countries having such 'excessive' climates seem almost condemned, as Dante expresses himself, "A sofferir tormenti caldi e geli."*

[fiitbite] *Dante, 'Divina Commedia, Purgatorio', canto iii.

In no portion of the earth, neither in the Canary Islands, in Spain, nor in the south of France, have I ever seen more luxuriant fruit, especially grapes, than in Astrachan, near the shores of the Caspian Sea (46 degrees 21'). Although the mean annual temperature is about 48ºdegrees, the mean summer heat rises to 70ºdegrees, as at Bordeaux, while not only there, but also further to the south, as at Kislar on the mouth of the Terek (in the latitude of Avignon and Rimini), the thermometer sinks in the winter to -13 degrees or -22 degrees.

Ireland, Guernsey, and Jersey, the peninsula of Brittany, the coasts of Normandy, and of the south of England, present, by the mildness of their winters, and by the low temperature and clouded sky of their summers, the most striking contrast to the continental climate of the interior of Eastern Europe. In the northeast of Ireland (54 degrees 56'), lying under the same parallel of latitude as Konigsberg in Prussia, the myrtle blooms as luxuriantly as in Portugal. The mean temperature of the month of August, which in Hungary rises to 70 degrees, scarcely reaches 61 degrees at Dublin, which is situated on the same isothermal line of 49 degrees; the mean winter temperature, which falls to about 28 degrees at Pesth, is 40 degrees at Dublin (whose mean annual temperature is not more than 49 degrees); 3.6 degrees higher than that of Milan, Pavia, Padua, and the whole of Lombardy, where the mean annual temperature is upward of 55ºdegrees. At Stromness, in the Orkneys, scarcely half a degree further south than Stockholm, the winter temperature is 39 degrees, and consequently higher than that of Paris, and neary as high as that of London. p 323 Even in the Faroe Islands, at 62 degrees latitude, the inland waters never freeze, owing to the favoring influence of the west winds and of the sea. On the charming coasts of Devonshire, near Salcombe Bay, which has been termed, on account of the mildness of its climate, the 'Montpellier of the North', the Agave Mexicana has been seen to blossoom in the open air, while orange-trees trained against espaliers, and only slightly protected by matting, are found to bear fruit. There, as well as at Penzance and Gosport, and at Cherbourg on the coast of Normandy, the mean winter temperature exceeds 42 degrees, falling short by only 2.4 degrees of the mean winter temperature of Montpellier and Florence.*

[footnote] *Humboldt, 'Sur les Lignes Isothermes', in the 'Memoires de Physique et de Chimie de la Societe d'Arcueil', t. iii., Paris, 1817, p. 143-165; Knight, in the 'Transactions of the Horticultural Society of London', vol. i, p. 32; Watson, 'Remarks on the Geographical Distribution of British Plants', 1835, p. 60; Trevelyan, in Jemieson's 'Edinburgh New Phil. Journal', No. 18, p. 154; Mahlmann in his admirable German translation of my 'Asie Centrale', th. ii., s. 60.

These observations will suffice to show the important influence exercised on vegetation and agriculture, on the cultivation of fruit, and on the comfort of mankind, by differences in the distribution of the same mean annual temperature, through the different seasons of the year.

The lines which I have termed 'Isochimenal' and 'isotheral' (lines of equal winter and equal summer temperature) are by no means parallel with the 'isothermal' lines (lines of equal annual temperature). If, for instance, in countries where myrtles grow wild, and the earth does not remain covered with snow in the winter, the temperature of the summer and autumn is barely sufficient to bring apples to perfect ripeness, and if, again, we observe that the grape rarely attains the ripeness necessary to convert it into wine, either in islands or in the vicinity of the sea, even when cultivated on a western coast, the reason must not be sought only in the low degree of summer heat, indicated, in littoral situations, by the thermometer when suspended in the shade, but likewise in another cause that has not hitherto been sufficiently considered, although it exercises an active influence on many other phenomena (as, for instance, in the inflammation of a mixture of chlorine and hydrogen), namely the difference between direct and diffused light, or that which prevails when the sky is clear and when it is overcast by mist. I long since endeavored to attract the attention of physicists and physiologists* to this p 324 difference, and to the 'unmeasured' heat which is locally developed in the living vegetable cell by the action of direct light.

[footnote] *"Haec de temperie aeris, qui terram late circumfundit, ac in quo, longe a solo, instrumenta nostra meteorologica suspensa habemus. Sed alia est caloris vis, quem radii solis nullis nubibus velati, in foliis ipsia et fructibus maturescentibus, magis minusve coloratis, gignunt, quemque, ut egregia demonstrant experimenta amicissimorum Gay-Lussacii et Thenardi de combustione chlori et hydrogenis, ope thermometri metiri nequis. Etenim locis planis et montanis, vento libe spirante, circumfusi aeris temperies cadem esse potest coelo sudo vel nebuloso; ideoque ex observationibus solis thermometricis, nullo adhibito Photometro, haud cognosces, quam ob causam Galliae septentrionalis tractur Armoricanus et Nervicus, versus littora, coe temperato sed sole raro utentia, Vitem fere non tolerant. Egent enim stirpes non solum caloris stimulo, sed et lucis, quae magis intensa locis excelsis quam planis, duplici modo plantas movet, vi sua tum propria, tum calorem in superficie earum excitante." -- Humboldt, 'De Distributione Geographica Plantarum', 1817, p. 163-164.

If, in forming a thermic scale of different kinds of cultivation,* we begin with those plants which require the hottest climate, as the vanilla, the cacao, banana, and cocoa-nut, and proceed to the pine-apples, the sugar-cane, coffee, fruit-bearing date-trees, the cotton-tree, citrons, olives, edible chestnuts, and fines producing potable wine, an exact geographical consideration of the limits of cultivation, both on plains and on the declivities of mountains, will teach us that other climatic relations besides those of mean annual temperature are involved in these phenomena.

[footnote] *Humboldt, op. cit., p. 156-161; Meyen, in his 'Grundriss der Pflanzengeographie', 1836 s. 379-467; Boussingault, 'Economie Rurale', t. ii., p. 675.

Taking an example, for instance, from the cultivation of the vine, we find that, in order to procure 'potable' wine,* it is requisite that the mean annual heat should exceed 49 degrees, that the winter temperature upward of 64 degrees.

[footnote] *the following table illustrates the cultivation of the vine in Europe, and also the depreciation of its produce according to climatic relations. See my 'Asie Centrale', t. iii., p. 159. The examples quoted in the text for Bordeaux and Potsdam are, in respect of numerical relation, alike applicable to the countries of the Rhine and Maine (48 degrees 35' to 40 degrees 7' N. lat.). Cherbourg in Normandy, and Ireland, show in th most remarkable manner how, with thermal relations very nearly similar to those prevailing in the interior of the Continent (as estimated by the thermometer in the shade), the results are nevertheless extremely different as regards the ripeness or the unripeness of the fruit of the vine, this difference undoubtedly depending on the circumstance whether the vegetation of the plant proceeds under a bright sunny sky, or under a sky that is habitually obscured by clouds:

[NB Table will line up in Courier 10 point]

_____________________________________________________________________ Places. Lat- Ele- Mean Win- Spring. Sum- Aut- Number of the it- va- of the ter. mer. umn. years of the tude tion. Year. observation

_____________________________________________________________________ deg ' Eng.ft. Fahr.

Bordeaux 44 50 25.6 57.0 43.0 56.0 71.0 58.0 10 Stras- 48 35 479.0 49.6 34.5 50.0 64.6 50.0 35 bourg Heid- 49 24 333.5 59.5 34.0 50.0 64.3 49.7 20 elberg Manheim 49 29 300.5 50.6 34.6 50.8 67.1 49.5 12 Wurzburg 49 48 562.5 50.2 35.5 50.5 65.7 49.4 27 Frank- fort on Maine 50 7 388.5 49.5 33.3 50.0 64.4 49.4 19 Berlin 52 31 102.3 47.5 31.0 46.6 63.6 47.5 23 Cher- bourg (no wine) 49 39 .... 52.1 41.5 50.8 61.7 54.2 3 Dublin (ditto) 53 23 .... 49.1 40.2 47.1 59.6 49.7 13 ___________________________________________________________________

The great accordance in the distribution of the annual temperature through the different seasons, as presented by the results obtained for the valleys of the Rhine and Maine, tends to confirm the accuracy of these meteorological observations. The months of December, January, and February are reckoned as winter months. When the different qualities of the wines produced in Franconia, and in the countries around the Baltic, are compared with the mean summer and autumn temperature of Wurzburg and Berlin, we are almost surprised to find a difference of only about two degrees. The difference in the spring is about four degrees. The influence of late May frosts on the flowering season, and after a correspondingly cold winter, is almost as important an element as the time of the subsequent ripening of the grape. The difference alluded to in the text between the true temperature of the surface of the ground and the indications of a thermometer suspended in the shade and protected from extraneous influences, is inferred by Dove from a consideration of the results of fifteen years' observations made at the Chiswick Gardens. See Dove, in 'Bericht uber die Verhandl. der Berl. Akad. der Wiss.', August, 1844, s. 285.

At Bordeaux, in the valley of the Garonne (44 degrees 50' lat.), the mean annual winter, summer, and autumn temperatures are respectively 57 degrees, 43 degrees, 71 degrees, and 58 degrees. In the plains near the p 325 Baltic (52 degrees 30' lat.), where a wine is produced that can scarcely be considered potable, these numbers are as follows: 47.5 degrees, 30 degrees, 63.7 degrees, and 47.5 degrees. If it should appear strange that the great differences indicated by the influence of climate on the production of wine should not be more clearly manifested by our thermometers, the circumstance will appear less singular when we remember that a thermometer standing in the shade, and protected from the effect of direct insolation and nocturnal radiation can not, at all seasong of the year, and during all periodic changes of heat, indicate the true superficial temperature of the ground exposed to the whole effect of the sun's rays.

The same relations which exist between the equable littoral climate of the peninsula of Brittany, and the lower winter and p 326 higher summer temperature of the remainder of the continent of France, are likewise manifested in some degree, between Europe and the great continent of Asia, of which the former may be considered to constitute the western peninsula. Europe owes its milder climate, in the first place, to its position with respect to Africa, whose wide extent of tropical land is favorable to the ascending current, while the equatorial region to the south of Asia is almost wholly oceanic; and next to its deeply-articulated configuration, to the vicinity of the ocean on its western shores; and, lastly, to the existence of an open sea, which bounds its northern confines. Europe would therefore become colder* if Africa were to be overflowed by the ocean; of if the mythical Atlantis were to arise and connect Europe with North America; or if the Gulf Stream were no longer to diffuse the warming influence of its waters into the North Sea; or if, finally, another mass of solid land should be upheaved by volcanic action, and interposed between the Scandinavian peninsula and Spitzbergen.

[footnote] *See my memoir, 'Ueber die Haupt-Ursachen der Temperaturverschiedenheit auf der Erdoberfläche', in the 'Abhandl. der Akad. der Wissensch. zu Berlin von dem Jahr' 1827, s. 311.

If we observe that in Europe the mean annual temperature falls as we proceed, from west to east, under the same parallel of latitude, from the Atlantic shores of France through Germany, Poland, and Russia, toward the Uralian Mountains, the main cause of this phenomenon of increasing cold must be sought in the form of the continent (which becomes less indented, and wider, and more compact as we advance), in the increasing distance from seas, and in the diminished influence of westerly winds. Beyond the Uralian Mountains these winds are converted into cool land-winds, blowing over extended tracts covered with ice and show. The cold of western Siberia is to be ascribed to these relations of configuration and atmospheric currents, and not -- as Hippocrates and Trogus Pompeius, and even celebrated travelers of the eighteenth century conjectures -- to the great elevation of the soil above the level of the sea.*

[footnote] *The general level of Siberia, from Tobolsk, Tomsk, and Barnaul, from the Altai Mountains to the Polar Sea, is not so high as that of Mauheim and Dresden; indeed, Irkutsk, far to the east of the Jenisei, is only 1330 feet above the level of the sea, or about one third lower than Munich.

If we pass from the differences of temperature manifested in the plains to the inequalities of the polyhedric form of the surface of our planet, we shall have to consider mountains either in relation to their influence on the climate of neighboring p 327 valleys, or according to the effects of the hyposometrical relations on their own summits, which often spread into elevated plateaux. The division of mountains into chains separates the earth's surface into different basins, which are often narrow and walled in, forming caldron-like valleys, and (as in Greece and in part of Asia Minor) constitute an individual local climate with respect to heat, moisture, transparancy of atmosphere, and frequency of winds and storms. These circumstances have at all times exercised a powerful influence on the character and cultivation of natural products, and on the manners and institutions of neighboring nations, and even on the feelings with which they regard one another. This character of 'geographical individuality' attains its maximum, if we may be allowed so to speak, in countries where the differences in the configuration of the soil are the greatest possible, either in a vertical or horizontal direction, both in relief and in the articulation of the continent. The greatest contrast to these varieties in the relations of the surface of the earth are manifested in the Steppes of Northern Asia, the grassy plains (savannahs, llanos, and pampas) of the New Continent, the heath ('Ericeta') of Europe, and the sandy and stony deserts of Africa.

The law of the decrease of heat with the increase of elevation at different latitudes is one of the most important subjects involved in the study of meteorological processes, of the geography of plants, of the theory of terrestrial refraction, and of the various hypotheses that relate to the determination of the height of the atmosphere. In the many mountain journeys which I have undertaken, both within and without the tropics, the investigation of this law has always formed a special object of my researches.*

[footnote] *Humboldt, 'Recueil d'Observations Astronomiques', t. i., p. 126-140; 'Relation Historique', t. i., p. 119, 141, 227; Biot, in 'Connaissance des Temps pour l'an' 1841, p. 90-109.

Since we have acquired a more accurate knowledge of the true relations of the distribution of heat on the surface of the earth, that is to say, of the inflections of isothermal and isotheral lines, and their unequal distance apart in the different eastern and western systems of temperature in Asia, Central Europe, and North America, we can no longer ask the general question, what fraction of the mean annual or summer temperature corresponds to the difference of one degree of geographical latitude, taken in the same meridian? In each system of 'isothermal' lines of equal curvature there reigns a p 328 close and necessary connection between three elements, namely, the decrease of heat in a vertical direction from below upward, the difference of temperature for every one degree of geographical latitude, and the uniformity in the mean temperature of a mountain station, and the latitude of a point situated at the level of the sea.

In the system of Eastern America, the mean annual temperature from the coast of Labrador to Boston changes 1.6ºdegrees for every degree of latitude; from Boston to Charleston about 1.7 degrees; from Charleston to the tropic of Cancer, in Cuba, the variation is less rapid, being only 1.2 degrees. In the tropics this diminution is so much greater, that from the Havana to Cumana the variation is less than 0.4 degrees for every degree of latitude.

The case is quite different in the isothermal system of Central Europe. Between the parallels of 38 degrees and 71 degrees I found that the decrease of temperature was very regularly 0.9degrees for every degree of latitude. But as, on the other hand, in Central Europe the decrease of heat is 1.8 degrees for about every 534 feet of vertical elevation, it follows that a difference of elevation of about 267 feet corresponds to the difference of one degree of latitude. The same mean annual temperature as that occurring at the Convent of St. Bernard, at an elevation of 8173 feet, in lat. 45 degrees 50' should therefore be met with at the level of the sea in lat. 75 degrees 50'.

In that part of the Cordilleras which falls within the tropics, the observations I made at various heights, at an elevation of upward of 19,000 feet, gave a decrease of 1 degree for every 341 feet; and my friend Boussingault found, thirty years afterward, as a mean result, 319 feet. By a comparison of places in the Cordilleras, lying at an equal elevation above the level of the sea, either on the declivities of the mountains or even on extensive elevated plateaux, I observed that in the latter there was an increase in the annual temperature varying from 2.7 degrees to 4.1 degrees. This difference would be still greater if it were not for the cooling effect of nocturnal radiation. As the different climates are arranged in successive strata, the one above the other, from the cacao woods of the valleys to the region of perpetual snow, and as the temperature in the tropics varies but little throughout the year, we may form to ourselves a tolerably correct representation of the climatic relations to which the inhabitants of the large cities in the Andes are subjected, by comparing these climates with the temperatures of particular months in the plains of France and Italy. While p 329 the heat which prevails daily on the woody shores of the Orinoco exceeds by 7.2 degrees that of the month of August at Palermo, we find, on ascending the chain of the Andes, at Popayan, at an elevation of 3826 feet, the temperature of the three summer months of Marseilles; at Quito, at an elevation of 9541 feet, that of the close of May at Paris; and on the Paramos, at a height of 11,510 feet, where only stunted Alpine shrubs grow, though flowers still bloom in abundance, that of the beginning of April at Paris. The intelligent observer, Peter Martyr de Aughiera, one of the friends of Christopher Columbus, seems to have been the first who recognized (in the expedition undertaken by Rodrigo Enrique Colmenares, in October, 1510) that the limit of perpetual snow continues to ascend as we approach the equator. We read, in the fine work 'De Rebus Oceanicis',* "the River Gaira comes from a mountain in the Sierra Nevada de Santa Maria, which, according to the testimony of the companions of Colmenares, is higher than any other mountain hitherto discovered.

[footnote] *Anglerius, 'De Rebus Oceanicis', Dec. xi., lib. ii., p. 140 (ed. Col., 1574). In the Sierra de Santa Marta, the highest point of which appears to exceed 19,000 feet (see my 'Relat. Hist.', t. ii., p. 214), there is a peak that is still called Pico de Gaira.

It must undoubtedly be so if 'it retain snow perpetually' in a zone which is not more than 10 degrees from the equinoctial line." The lower limit of perpetual snow, in a given latitude, is the lowest line at which snow continues during summer, or, in other words, it is the maximum of height to which the snow-line recedes in the course of the year. But this elevation must be distinguished from three other phenomena, namely, the annual fluctuation of the snow-line, the occurrence of sporadic falls of snow, and the existence of glaciers, which appear to be peculiar to the temperate and cold zones. This last phenomenon, since Saussure's immortal work on the Alps, has received much light, in recent times, from the labors of Venetz, Charpentier, and the intrepid and persevering observer Agassiz.

We know only the 'lower', and not the 'upper' limit of perpetual snow; for the mountains of the earth do not attain to those ethereal regions of the rarefied and dry strata of air, in which we may suppose, with Bouguer, that the vesicles of aqueous vapor are converted into crystals of ice, and thus rendered perceptible to our organs of sight. The lower limit of snow is not, however, a mere function of geographical latitude or of mean annual temperature; nor is it at the equator, or p 330 even, in the region of the tropics, that this limit attains its greatest elevation above the level of the sea. The phenomenon of which we are treating is extremely complicated, depending on the general relations of temperature and humidity, and on the form of the mountains. On submitting these relations to the test of special analysis, as we may be permitted to do from the number of determinations that have recently been made,* we shall find that the controlling causes are the differences in the temperature of different seasons of the year; the direction of the prevailing winds and their relations to this land and sea; the degree of dryness or humitidy in the upper strata of the air; the absolute thickness of the accumulated masses of fallen snow; the relation of the s-line to the total height of the mountain; the relative position of the latter in the chain to which it belongs, and the steepness of its declivity; the vicinity of either summits likewise perpetually covered with show; the expansion, position, and elevation of the plains from which the snow mountain rises as an isolated peak or as a portion of a chain; whether this plain be part of the sea-coast, or of the interior of a continent; whether it be covered with wood or waving grass; and whether, finally, it consist of a dry and rocky soil, or of a wet and marshy bottom.

[footnote] *See my table of the height of the line of perpetual snow, in both hemispheres, from 71 degrees 15' north lat. to 53 degrees 54' south lat., in my 'Asie Centrale', t. iii., p. 360.

The snow-line which, under the equator in South America, attains an elevation equal to that of the summit of Mont Blanc in the Alps, and descends, according to recent measurements, about 1023 feet lower toward the northern tropic in the elevated plateaux of Mexico (in 19 degrees north latitude), rises, according to Pentland, in the southern tropical zone (14 degrees 30' to 18 degrees south latitude), being more than 2665 feet higher in the maritime and western branch of the Cordilleras of Chili than under the equator near Quito on Chimborazo, Cotopaxi, and Antisana. Dr. Gilles even asserts that much further to the south, on the declivity of the volcano of Peuquenes (latitude 33 degrees), he found the snow-line at an elevation of between 14,520 and 15,030 feet. The evaporation of the snow in the extremely dry air of the summer, and under a cloudless sky, is so powerful, that the volcano of Aconcagua, northeast of Valparaiso (latitude 32 degrees 30'), which was found in the expedition of the Beagle to be more than 1400 feet higher than Chimborazo, was on one occasion seen free from snow.•

[footnote] *Darwin, 'Journal of the Voyages of the Adventure and Beagle', p. 297. As the volcano of Aconcagua was not at that time in a state of eruption, we must not ascribe the remarkable phenomenon of this absence of snow to the internal heat of the mountain (to the escape of heated air through fissures), as is sometimes the case with Cotopaxi. Gilles, in the 'Journal of Natural Science', 1830, p. 316.

In p 331 an almost equal northern latitude (from 30 degrees 45' to 31 degrees), the snow'line on the southern declivity of the Himalaya lies at an elevation of 12,982 feet, which is about the same as the height which we might have assigned to it from a comparison with other mountain chains; on the northern declivity, however, under the influence of the high lands of Thibet (whose mean elevation appears to be about 11,510 feet), the snow-line is situated at a height of 16,630 feet. This phenomenon, which has long been contested both in Europe and in India, and whose causes I have attempted to develop in various works, published since 1820,* possesses other grounds of interest than p 332 those of a purely physical nature, since it exercises no inconsiderable degree of influence on the mode of life of numerous tribes -- the meteorological processes of the atmosphere being the controlling causes on which depend the agricultural or pastoral pursuits of the inhabitants of extensive tracts of continents.

[footnote] *See my 'Second Memoire sur les Montagnes de Inde', in the 'Annales de Chemie et de Physique', t. xiv., p. 5-55; and 'Asie Centrale', t. iii., p. 281-327. While the most learned and experienced travelers in India, Colebrooke, Webb, and Hodgson, Victor Jacquemont, Fobes Royle, Carl von Hugel, and Vigne, who have all personally examined the Himalaya range, are agreed, regarding the greater elevation of the snow-line on the Thibeta=ian side, the accuracy of this statement is called in question by John Gerard, by the geognoist MacClelland, the editor of the 'Calcutta Journal', and by Captain Thomas Hutton, assistant surveyor of the Agra Division. The appearance of my work on Central Asia gave rise to a rediscussion of this question. A recent number (vol. iv., January, 1844) of MacClelland and Griffith's 'Calcutta Journal of Natural History' contains, however, a very remarkable and decisive notice of the determination of the snow-line in the Himalaya. Mr. Batten, of the Bengal service, writes as follows from Camp Semulka, on the Cosillah River, Kumaon: "In the July, 1843, No. 14 of your valuable Journal of Natural History, which I have only lately had the opportunity of seeing, I read Captain Hutton's paper on the snow of the Himalayas, and as I differed almost entirely from the conclusions so confidently drawn by that gentleman, I thought it right, for the interest of scientific truth, to prepare some kind of answer; as however, on a more attentive perusal, I find that you yourself appear implicitly to adopt Captain Hutton's views, and actually use these words, 'We have long been conscious of the error here so well ppointed out by Captain Hutton, 'in common with every one who has visited the Himalayas,' I feel more inclined to address you, in the first instance, and to ask whether you will publish a short reply which I meditate; and whether your not to Captain Hutton's paper was written after your own full and careful examination of the subject, or merely on a general kind of acquiscence with the fact and opinions of your able contributor, who is so well known and esteemed as a collector of scientific data? Now I am one who have visited the Himalaya on the western side; I have crossed the Borendo or Booria Pass into the Buspa Valley, in Lower Kanawar, returning into the Rewaien Mountains of Ghurwal by the Koopin Pass; I have visited the source of the Jumna at Jumnootree; and, moving eastward, the sources of the Kalee or Mundaknee branch of the Ganges at Kadarnath; of the Bishnoo Gunga, or Aluknunda, at Buddrinath and Mana; of the Pindur at the foot of the Great Peak Nundidavi; of the Dhoulee branch of the Ganges, beyond Neetee, crossing and recrossing the pass of that name into Thibet; of the Goree or great branch of the Sardah, or Kalee, near Oonta Dhoora, beyond Melum. I have also, in my official capacity made the settlement of the Bhote Mehals of this province. My residence of more than six years in the hills has thrown me constantly in the way of European and native travelers, nor have I neglected to acquire information from the recorded labors of others. Yet, with all this experience, I am prepared to affirm that 'the perpetual snow-line is at a higher elevation' on the northern slope of 'the Himalaya' than on the southern slope. "The facts mentioned by Captain Hutton appear to me only to refer to the northern sides of all mountains in these regions, and not to affect, in any way the reports of Captain Webb and others, on which Humboldt formed his theory. Indeed how can any facts of one observer in one place falsify the facts of another observer in another place? I willingly allow that the north side of a hill retains the snow longer and deeper than the south side, and this observation applies equally to heights in Bhote; but Humboldt's theory is on the question of the perpetual snow-line, and Captain Hutton's reference to Simla and Mussooree, and other mountain sites, are out of place in this question, or else he fights against a shadow, or an objectioon of his own creation. In no part of his paper does he quote accurately the dictum which he wishes to oppose." If the mean altitude of the thibetian highlands be 11,510 feet, they admit of comparison with the lovely and fruitful plateau of Caxamarca in Peru. But at this estimate they would still be 1300 feet lower than the plateau of Bolivia at the Lake of Titicaca, and the causeway of the town of Potosi. Ladak, as appears from Vigne's measurement, by determining the boiling-point, is 9994 feet high. This is probably also the altitude of H'Lassa (Yul-sung), a monastic city, which Chinese writers describe as the 'realm of pleasure', and which is surrounded by vineyards. Must not these lie in deep valleys?

As the quantity of moisture in the atmosphere increases with the temperature, this element, which is so important for the whole organic creation, must vary with the hours of the day, the seasons of the year, and the differences in latitude and elevation. Our knowledge of the hygrometric relations of the Earth's surface has been very materially augmented of late years by the general application of August's psychrometer, framed in accordance with the views of Dalton and Daniell, for determining the relative quantity of vapor, or the p 333 condition of moisture of the atmosphere, by means of the difference of the 'dew point' and of the temperature of the air. Temperature, atmospheric pressure, and the direction of the wind, are all intimately connected with the vivifying action of atmospheric moisture. This influence is not, however, so much a consequence of the quantity of moisture held in solution in different zones, as of the nature and frequency of the precipitation which moistens the ground, whether in the form of dew, mist, rain, or snow. According to the exposition made by Dove of the law of rotation, and to the general views of this distinguished physicist,* it would appear that, in our northern zone, "the elastic force of the vapor is greatest with a southwest, and least with a northeast wind. On the western side of the windrose this elasticity diminishes, while it increases on the eastern side; on the former side, for instance, the cold, dense, and dry current of air repels the warmer, lighter current containing an abundance of aqueous vapor, while on the eastern side it is the former current which is repulsed by the latter.

[footnote] *See Dove, 'Meteorologische Vergleichung von Nordamerika und Europa', in Schumacher's 'Jahrbuch fur' 1841, s. 311; and his 'Meteorologische Untersuchungen', s. 140.

The agreeable and fresh verdure which is observed in many trees in districts within the tropics, where, for five or seven months of the yeqar, not a cloud is seen on the vault of heaven, and where no perceptible dew or rain falls, proves that the leaves are capable of extyracting water from the atmosphere by a peculiar vital process of their own, which perhaps is not alone that of producing cold by radiation. The absence of rain in the arid plains of Cumana, Coro, and Ceara in North Brazil, forms a striking contrast to the quanitity of rain which falls in some tropical regions, as, for instance, in the Havana, where it would appear, from the average of six years' observation by Ramong de la Sagra, the mean annual quantity of rain is 109 inches, equal to four or five times that which falls at Paris or at Geneva.*

[footnote] *The mean annual quantity of rain that fell in Paris between 1805 and 1822 was found by Arago to be 20 inches; in London, between 1812 and 1827, it was determined by Howard at 25 inches; while at Geneva the mean of thirty-two years' observation was 30.5 inches. In Hindostan, near the coast, the quantity of rain is from 115 to 128 inches; and in the island of Cuba, fully 142 inches fell in the year 1821. With regard to the distribution of the quantity of rain in Central Europe, at different periods of the year, see the admirable researches of Gasparin, Schuow, and Bravais, in the 'Bibliotheque Universelle', t. xxxvviii., p. 54 and 264; 'Tableau du Climat de l'Italie', p. 76; and Martins's notes to his excellent French translation of Kämtz's 'Vorlesungen uber Meteorologie', p. 142.

On the declivity of the Cordilleras, p 334 the quantity of rain, as well as the temperature, diminishes with the increase in the elevation.*

[footnote] *According to Boussingault ('Economie Rurale', t. ii., p. 693), the mean quantity of rain that fell at Marmato (latitude 5 degrees 27', altitude 4675 feet, and mean temperature 69 degrees) in the years 1833 and 1834 was 64 inches, while at Santa Fe de Bogota (latitude 4 degrees 36', altitude 8685 feet, and mean temperature 58 degrees) it only amounted to 39 1/2 inches.

My South American fellow-traveler, Caldas, found that, at Santa Fe de Bogota, at an elevation of almost 8700 feet, it did not exceed 37 inches, being consequently little more than on some parts of the western shore of Europe. Boussingault occasionally observed at Quito that Saussure's hygrometer receded to 26 degrees with a temperature of from 53.6 degrees to 55.4 degrees. Gay-Lussac saw the same hygrometer standing at 25.3 degrees in his great aerostatic ascent in a stratum of air 7034 feet high, and with a temperature of 39.2 degrees. The greatest dryness that has yet been observed on the surface of the globe in the low lands is probably that which Gustav Rose, Ehrenberg, and myself found in Northern Asia, between the valleys of the Irtisch and the Oby. In the Steppe of Platowskaja, after southwest winds had blown for a long time from the interior of the Continent, with a temperature of 74.7 degrees, we found the dew point at 24 degrees. The air contained only 16/100ths of aqueous vapor.*

[footnote] *For the particulars of this observation, see my 'Asie Centrale', t. iii., p. 85-89 and 467; and regarding the amount of vapor in the atmosphere in the lowlands of tropical South America, consult my 'Relat. Hist.', t. i., p. 242-248; t. ii., p. 45, 164.

The accurate observers Kämtz, Bravais, and Martins have raised doubts during the last few years regarding the greater dryness of the mountain air, which appeared to be proved by the hygrometric measurements made by Saussure and myself in the higher regions of the Alps and the Cordilleras. The strata of air at Zurich and on the Faulhorn, which can not be considered as an elevated mountain when compared with non-European elevations, furnished the data employed in the comparisons made by these observers.*

[footnote] *Kämtz, 'Vorlesungen uber Meteorologie', s. 117.

In the tropical region of the Paramos (near the region where snow begins to fall, at an elevation of between 12,000 and 14,000 feet), some species of large flowering myrtle-leaved alpine shrubs are almost constantly bathed in moisture; but this fqact does not actually prove the existence of any great and absolute quantity of aqueous vapor at such an elevation, merely affording p 335 an evidence of the frequency of aqueous precipitation, in like manner as do the frequent mists with which the lovely plateau of Bogota is covered. Mists arise and disappear several times in the course of an hour in such elevations as these, and with a calm state of the atmosphere. These rapid alternations characterize the Paramos and the elevated plains of the chain of the Andes.

'The electricity of the atmosphere', whether considered in the lower or in the upper strata of the clouds, in its silent problematical diurnal course, or in the explosion of the lightning and thunder of the tempest, appears to stand in a manifold relation to all phenomena of the distribution of heat, of the pressure of the atmosphere and its disturbances, of hydrometeoric exhibitions, and probably, also, of the magnetism of the external crust of the earth. It exercises a powerful influence on the whole animal and vegetable world; not merely by meteorological processes, as precipitations of aqueous vapor, and of the acids and ammoniacal compounds to which it gives rise, but also directly as an electric force acting on the nerves, and promoting the circulation of the organic juices. This is not a place in which to renew the discussion that has been started regarding the actual source of atmospheric eletricity when the sky is clear, a phenomenon that has alternately been ascribed to the evaporation of impure fluids impregnated with earths and salts,* to the growth of plants,** or to some other chemical decompositions on the surface of the earth, to the unequal distribution of heat in the strata of the air,*** and, finally, according to Peltier's intelligent researches,**** to the agency of a constant charge of negative electricity in the terrestrial globe.

[footnote] *Regarding the conditions of electricity from evaporation at high temperatures, see Peltier, in the 'Annales de Chimie', t. lxxv., p. 330.

[footnote] **Pouillet, in the 'Annales de Chimie', t. xxxv., p. 405.

[footnote] ***De la Rive, in his admirable 'Essai Historique sur l'Electricite', p. 140.

[footnote] ****Peltier, in the 'Comptes Rendus de l'Acad. des Sciences', t. xii., p. 307; Becquerel, 'Traite de l'Electricite et du Magnetisme', t. iv., p. 107.

Limiting itself to results yielded by electrometric observations, such, for instance, as are furnished by the ingenious electro-magnetic apparatus first proposed by Colladon, the physical description of the universe should merely notice the incontestable increase of intensity in the general positive electricity of the atmosphere,* accompanying an increase of altitude and and the absence of trees, its daily variations (which, according to Clark's experiments at Dublin, p 336 take place at more complicated periods than those found by Saussure and myself), and its variations in the different seasons of the year, at different distances from the equator, and in the different relations of continental or oceanic surface.

[footnote] *Duprez, 'Sur l'Electricite de l'Air' (Bruxelles, 1844), p. 56-61.

The electric equilibrium is less frequently disturbed where the aerial ocean rests on a liquid base than where it impends over the land; and it is very striking to observe how, in extensive seas, small insular groups affect the condition of the atmosphere, and occasion the formation of storms. In fogs, and in the commencement of falls of snow, I have seen, in a long series of observations, the previously permanent positive electricity rapidly pass into the negative condition, both on the plains of the colder zones, and in the Paramos of the Cordilleras, at elevations varying from 11,000 to 15,000 feet. The alternate transition was precisly similar to that indicated by the electrometer shortly before and during a storm.*

[footnote] *Humboldt, 'Relation Historique', t. iii., p. 318. I here only refer to those of my experiiments in which the three-foot metallic conductor of Saussure's electrometer was neither moved upward nor downward, nor, according to Volta's proposal, armed with burning sponge. Those of my readers who are well acquainted with the 'quaestiones vexatae' of atmospheric electricity will understand the grounds for this limitation. Respecting the formation of storms in the tropics, see my 'Rel. Hist.', t. ii., p. 45 and 202-209.

When the vesicles of vapor have become condensed into clouds, having definite outlines, the electric tension of the external surface will be increased in proportion to the amount of electricity which passes over to it from the separate vesicles of vapor.*

[footnote] *Gay-Lussac, in the 'Annales de Chimie et de Physique', t. viii., p. 167. In consequence of the discordant views of Lame, Becquerel, and Peltier, it is difficult to come to a conclusion regarding the cause of the specific distribution of electricity in clouds, some of which have a positive, and others a negative tension. The negative electricity of the air, which near high water-falls is caused by a disintegration of the drops of water -- a fact originally noticed by Tralles, and confirmed by myself in various latitudes -- is very remarkable, and is sufficiently intense to produce an appreciable effect on a delicate electrometer at a distance of 300 or 400 feet.

Slate-gray clouds are charged, according to Peltier's experiments at Paris, with negative, and white, red, and orange-colored clouds with positive electricity. Thunder clouds not only envelop the highest summits of the chain of the Andes (I have myself seen the electric effect of lightning on one of the rocky pinnacles which project upward of 15,000 feet above the crater of the volcano of Toluca), but they have also been observed at a vertical height of 26,650 feet over the low p 337 lands in the temperate zone.*

[footnote] *Arago, in the 'Annuaire du Bureau des Longitudes pour' 1838, p. 246.

Sometimes, however, the stratum of cloud from which the thunder proceeds sinks to a distance of 5000, or, indeed, only 3000 feet above the plain.

According to Arago's investigations -- the most comprehensive that we possess on this difficult branch of meteorology -- the evolution of light (lightning) is of three kinds -- zigzag, and sharply defined at the edges; in sheets of light, illuminating a whole cloud, which seems to open and refeal the light within it; and in the form of fire-balls.*

[footnote] *Arago, op. cit., p. 249-266. (See also, p. 268-279.)

The duration of the two first kinds scarcely continues the thousandth part of a second; but the globular lightning moves much more slowly remaining visible for several seconds. Occasionally (as is proved by the recent observations, which have confirmed the description given by Nicholson and Beccaria of this phenomenon), isolated clouds, standing high above the horizon, continue uninterruptedly for some time to emit a luminous radiance from their interior and from their margins, although there is no thunder to be heard, and no indication of a storm; in some cases even hail-stones, drops of rain, and flakes of snow have been seen to fall in a luminous condition, when the phenomenon was not preceded by thunder. In the geographical distribution of storms, the Peruvian coast, which is not visited by thunder or lightning, presents the most striking contrast to the rest of the tropical zone, in which, at certain seasons of the year, thunder-storms occur almost daily, about four or five hours after the sun has reached the meridian. According to the abundant evidence collected by Arago* from the testiimony of navigators (Scoresby, Parry, Ross, and Franklin), there can be no doubt that, in general, electric explosions are extremely rare in high northern regions (between 70 degrees and 75 degrees latitude).

[footnote] *Arago, op. cit., p. 388-391. The learned academician Von Baer, who has done so much for the meteorology of Northern Asia, has not taken into consideration the extreme rarity of storms in Iceland and Greenland; he has only remarked ('Bulletin de l'Academie de St. Petersbourg', 1839, Mai) that in Nova Zembla and Spitzbergen it is sometimes heard to thunder.

'The meteorological portion' of the descriptive history of nature which we are now concluding shows that the processes of the absorption of light, the liberation of heat, and the variations in the elastic and electric tension, and in the hygrometric condition of the vast aerial ocean, are all so intimately connected together, that each individual meteorological process is modified by the action of all the others. The complicated p 338 nature of these disturbing causes (which involuntarily remind us of those which the near and especially the smallest cosmical bodies, the satellites, comets, and shooting stars, are subjected to in their course) increases the difficulty of giving a full explanation of these involved meteorological phenomena, and likewise limits, or wholly precludes, the possibility of that predetermination of atmospheric changes which would be so important for horticulture, agriculture, and navigation, no less than for the comfort and enjoyment of life. Those who place the value of meteorology in this problematic species of prediction rather than in the knowledge of the phenomena themselves, are firmly convinced that this branch of science, on account of which so many expeditions to distant mountainous regions have been undertaken, has not made any very considerable progress for centuries past. The confidence which they refuse to the physicist they yield to changes of the moon, and to certain days marked in the calendar by the superstition of a by-gone age.

"Great local deviations from the distribution of the mean temperature are of rare occurrence, the variations being in general uniformly distributed over extensive tracts of land. the deviation, after attaining its maximum at a certain point, gradually decreases to its limits; when these are passed, however, decided deviations are observed in the 'opposite direction'. Similar relations of weather extend more frequently from south to north than from west to east. At the close of the year 1829 (when I had just completed my Siberian journey), the maximum of cold was at Berlin, while North America enjoyed an unusually high temperature. It is an entirely arbitrary assumption to believe that a hot summer succeeds a severe winter, and that a cool summer is preceded by a mild winter." Opposite relations of weather in contiguous countries, or in two corn-growing continents, give rise to a beneficient equalization in the prices of the products of the vine, and of agricultural and horticultural cultivation. It has been justy remarked, that it is the barometer alone which indicates to us the changes that occur in the pressure of the air throughout all the aerial strata from the place of observation to the extremest confines of the atmosphere, while* the thermometer and psychrometer only acquaint us with all the variations occurring in the local heat and moisture of the lower strata of p 339 air in contact with the ground.

[footnote] *Kämtz, in Schumacher's 'Jahrbuch fur' 1838, s. 285. Regarding the opposite distribution of heat in the east and the west of Europe and North America, see Dove, 'Repertorium der Physik', bd. iii., s. 392-395.

The simultaneous thermic and hygrometric modifications of the upper regions of the air can only be learned (when direct observations on mountain stations or aerostatic ascents are impracticable) from hypothetical combinations, by making the barometer serve both as a thermometer and an hygrometer. Important changes of weather are not owing to merely local causes, situated at the place of observation, but are the consequence of a disturbance in the equilibrium of the aerial currents at a great distance from the surface of the Earth, in the higher strata of the atmosphere, bringing cold or warm, dry or moist air, rendering the sky cloudy or serene, and converting the accumulated masses of clouds into light feathery 'cirri'. As, therefore, the inaccessibility of the phenomenon is added to the manifold nature and complication of the disturbances, it has always appeared to me that meteorology must first seek its foundation and progress in the torrid zone, where the variations of the atmospheric pressure, the course of hydro-meteors, and the phenomena of electric explosion, are all of periodic occurrence.

As we have now passed in review the whole sphere of inorganic terrestrial life, and have briefly considered our planet with reference to its form, its internal heat, its electro-magnetic tension, its phenomena of polar light, the volcanic reaction of its interior on its variously composed solid crust, and, lastly, the phenomena of its two-fold envelopes -- the aerial and liquid ocean -- we might, in accordance with the older method of treating physical geography, consider that we had completed our descriptive history of the globe. But the nobler aim I have proposed to myself, of raising the contemplation of nature to a more elevated point of view, would be defeated, and this delineation of nature would appear to lose its most attractive charm, if it did not also include the sphere of organic life in the many stages of its typical development. The idea of vitality is so intimatey associated with the idea of the existence of the active, ever-blending natural forces which animate the terrestrial sphere, that the creation of plants and animals is ascribed in the most ancient mythical representations of many nations to these forces, while the condition of the surface of our planet, before it was animated by vital forms, is regarded as coeval with the epoch of a chaotic conflict of the struggling elements. But the empirical domain of objective contemplation, and the delineation of our planet in its present condition, do not include a consideration p 340 of the mysterious and insoluble problems of origin and existence.

A cosmical history of the universe, resting upon facts as its basis, has, from the nature and limitations of its sphere, necessarily no connection with the obscure domain embraced by a 'history of organisms',* if we understand the word 'history' in its broadest sense.

[footnote] *The 'history of plants', which Endlicher and Unger have described in a most masterly manner ('Grundzuge der Botanik', 1843, s. 449-468), I myself separated from the 'geography of plants' half a century ago. In the aphorisms appended to my 'Subterranean Flora', the following passage occurs: "Geognosia naturam animantem et inanimam vel, ut vocabulo minus apto, ex antiquitate saltem haud petito, utar, corpora vitur capita: Geographia oryctologica quam simpliciter Geognosiam vel Geologiam dicunt, virque acutissimus Wernerus egregie digessit; Geographia zoologica, cujus doctrinae fundamenta Zimmermannus et Treviranus jecerunt; et Geographic plantarum quam aequales nostri diu intactam reliquerunt. Geographia plantarum vincula et cognationem tradit, quibus omnia vegetabilia inter se connexa sint, terraetractur quos teneant, in aerem atmosphaericum quae sit eorum vis ostendit, saxa atque rupes quibus potissimum algarum primordiis radicibusque destruantur docet, et quo pacto in telluris superficie humus nascatur, commemorat. Est itaque quod differat inter Geognosiam et Physiographiam, 'historia naturalis' perperam nuncupatam quum Zoognosia, Phytognosia, et Oryctognosia, quae quidem omnes in naturae investigatione versantur, non nisi singulorum animalium, plantarum, rerum metallicarum vel (venia sit verbo) fossilium formas, anatomen, vires scrutautur. Historia Telluris, Geognosiae magis quam Physiographiae affinis, nemini adhuc tenata, plantarum animaliumque genera orbem inhabitantia primaevum, migrationes eorum compluriumque interitum, ortum quem montes, valles, saxorum strata et vemae metalliferae ducunt, aerem, mutatis temporum vicibus, modo purum, modo vitiatum, terrae superficiem humo plantisque paulatim obtectam, fluminum inundantium impetu denuo nudatam, iterumque siccatam et gramine vestitam commemorat. Igitur Historia zoolopgica, Historia plantarum et Historia oryctologica, quae non nisi pristinum orbis terrae statum indicant, a Geognosia probe distinguendae." -- Humboldt, 'Flora Friburgensis Subterranea, cui accedunt Aphorismi ex Physiologia Chemica Plantarum', 1793, p. ix.-x. Respecting the "spontaneous motion." which is referred to in a subsequent part of the text, see the remarkable passage in Aristotle, 'De Coelo,' ii., 2, p. 284, Bekker, where the distinction between animate and inanimate bodies is made to depend on the internal or external position of the seat of the determining motion. "No movement," says the Stagirite, "proceeds from the vegetable spirit, because plants are buried in a still sleep, from which nothing can arouse them" (Aristotle, 'De Generat. Animal.', v. i., p. 778, Bekker); and again, "because plants have no desires which incite them to spontaneous motion." (Arist., 'De Somno et Vigil'., cap. i., p. 455, Bekker.)

It must, however, be remembered, that the inorganic crust of the Earth contains within it the same elements that enter into the structure of animal and vegetable organs. A physical cosmography would therefore be incomplete p 341 if it were to omit a consideration of these forces, and of the substances which enter into solid and fluid combinations in organic tissues, under conditiions which, from our ignorance of their actual nature, we designate by the vague term of 'vital forces', and group into various systems in accordance with more or less perfectly conceived analogies. The natural tendency of the human mind involuntarily prompts us to follow the physical phenomena of the Earth, through all their varied series, until we reach the final stage of the morphological evolution of vegetable forms, and the self-determining powers of motion in animal organisms. And it is by these links that 'the geography of organic beings -- of plants and animals' -- is connected with the delineation of the inorganic phenomena of our terrestrial globe.

Without entering on the difficult question of 'spontaneous motion', or, in other words, on the difference between vegetable and animal life, we would remark, that if nature had endowed us with microscopic powers of vision, and the integuments of plants had been rendered perfectly transparent to our eyes, the vegetable world would present a very different aspect from the apparent immobility and repose in which it is now manifested to our senses. The interior portion of the cellular structure of their organs is incessantly animated by the most varied currents, either rotating, ascending and descending, remifying, and ever changing their direction, as manifested in the motion of the granular mucus of marine plants (Naiades, Characeae, Hydrocharidae), and in the hairs of phanerogamic land plants; in the molecular motion first discovered by the illustrious botanist Robert Brown, and which may be traced in the ultimate portions of every molecule of matter, even when separated from the organ; in the gyratory currents of the globules of cambium ('cyclosis') circulating in their peculiar vessels; and, finally, in the singularly articulated self-unrolling filamentous vessels in the antheridia of the chara, and in the reproductive organs of liverworts and algae, in the structural conditions of which Meyen, unhappily too early lost to science, believed that he recognized an analogy with the spermatozoa of the animal kingdom.*

[footnote] *["In certain parts, probably, of all plants, are found peculiar spiral filaments, having a striking resemblance to the spermatozoa of animals. They have been long known in the organs called the antheridia of mosses, Hepaticcae, and Characeae, and have more recently been discovered in peculiar cells on the germinal frond of ferns, and on the very young leaves of the buds of Phanerogamia. They are found in peculiar cells, and when these are placed in water they are torn by the filament, which commences an

## active spiral motion. The signification of these organs is at present quite

unknown; they appear, from the researches of Nägeli, to resemble the cell mucilage, or proto-plasma, in composition, and are developed from it. Schleiden regards them as mere mucilaginous deposits, similar to those connected with the circulation in cells, and he contends that the movement of these bodies in water is analogous to the molecular motion of small

## particles of organic and inorganic substances, and depends on mechanical

causes." -- 'Outlines of Structural and Physiological Botany', by A. Henfrey, F.L.S., etc., 1846, p. 23.] -- Tr.

If to these p 342 manifold currents and gyratory movements we add the phenomena of endosmosis, nutrition, and growth, we shall have some idea of those forces which are ever active amid the apparent repose of vegetable life.

Since I attempted in a former work, 'Ansichten der Natur' (Views of Nature), to delineate the universal diffusion of life over the whole surface of the Earth, in the distribution of organic forms, both with respect to elevation and depth, our knowledge of this branch of science has been most remarkably increased by Ehrenberg's brilliant discovery "on microscopic life in the ocean, and in the ice of the polar regions" -- a discovery based, not on deductive conclusions, but on direct observation. The sphere of vitality, we might almost say, the horizon of life, has been expanded before our eyes. "Not only in the polar regions is there an uninterrupted development of

## active microscopic life, where larger animals can no longer exist, but we

find that the microscopic animals collected in the Antarctic expedition of Captain James Ross exhibit a remarkable abundance of unknown and often most beautiful forms. Even in the residuum obtained from the melted ice, swimming about in round fragments in the latitude of 70 degrees 10', there were found upward of fifty species of silicious-shelled Polygastria and Coscinodiscae with their green ovaries, and therefore living and able to resist the extreme severity of the cold. In the Gulf of Erebus, sixty-eight silicious-shelled Polygastria and Phytolitharia, and only one calcareous-shelled Polythalamia, were brought up by lead sunk to a depth of from 1242 to 1620 feet."

The greater number of the oceanic microscopic forms hitherto discovered have been silicious-shelled, although the analysis of sea water does not yield silica as the main constituent, and it can only be imagined to exist in it in a state of suspension. It is not only at particular points in inland seas, or in the vicinity of the land, that the ocean is densely inhabited by living atoms, invisible to the naked eye, but samples of p 343 water taken up by Schayer on his return from Van Diemen's Land (south of the Cape of Good Hope, in 57 degrees latitude, and under the tropics in the Atlantic) show that the ocean in its ordinary condition, without any apparent discoloration, contains numerous microscopic moving organisms, which bear no resemblance to the swimming fragmentary silicious filaments of the genus Chaetoceros, similar to the Oscillatoriae so common in our fresh waters. Some few Polygastria, which have been found mixed with sand and excrements of penguins in Cockburn Island, appear to be spread over the whole earth, while others seem to be peculiar to the polar regions.*

[footnote] *See Ehrenberg's treatise 'Ueber das kleinste Leben im Ocean', read before the Academy of Science at Berlin on the 9th of May, 1844. [Dr. J. Hooker found Diatomaceae in countless numbers between the parallels of 70 degrees and 80 degrees south, where they gave a color to the sea, and also the icebergs floating in it. The death of these bodies in the South Arctic Ocean is producing a submarine deposit, consisting entirely of the silicious particles of which the skeletons of these vegetables are composed. This deposit exists on the shores of Victoria Land and at the base of the volcanic mountain Erebus. Dr. Hooker accounted for the fact that the skeletons of Diatomaceae had been found in the lava of volcanic mountains, by referring to these deposits at Mount Erebus, which lie in such a position as to render it quite possible that the skeletons of these vegetables should pass into the lower fissures of the mountain, and then passing into the stream of lava, be thrown out, unacted upon by the heat to which they have been exposed. See Dr. Hooker's Paper, read before the British Association at Oxford, July, 1847.] -- Tr.

We thus find from the most recent observations that animal life predominates amid the eternal night of the depths of ocean, while vegetable life, which is so dependent on the periodic action of the solar rays, is most prevalent on continents. The mass of vegetation on the Earth very far exceeds that of animal organisms; for what is the volume of all the large living Cetacea and Pachydermata when compared with the thickly-crosded colossal trunks of trees, of from eight to twelve feet in diameter, which fill the vast forests covering the tropical region of South America, between the Orinoco, the Amazon, and the Rio de Madeira? And although the character of different portions of the earth depends on the combination of external phenomena, as the outlines of mountains -- the physiognomy of plants and animals -- the azure of the sky -- the forms of the clouds -- and the transparency of the atmosphere -- it must still be admitted that the vegetable mantle with which the earth is decked constitutes the main feature of the picture. Animal forms are inferior in mass, and their powers of motion often withdraw them from our sight. The p 344 vegetable kingdom, on the contrary, acts upon our imagination by its continued presence and by the magnitude of its forms; for the size of a tree indicates its age, and here alone age is associated with the expression of a constantly renewed vigor.*

[footnote] *Humboldt, 'Ansichten der Natur' (2te Ausgabe, 1826), bd. ii. s. 21.

In the animal kingdom (and this knowledge is also the result of Ehrenberg's discoveries), the form which we term microscopic occupy the largest space, in consequence of their rapid propagation.*

[footnote] *On multiplication by spontaneous division of the mother-corpuscle and intercalation of new substance, see Ehrenberg 'Van den jetzt lebenden Thierarten der Kreidebildung', in the 'Abhandl. der Berliner Akad. der Wiss.', 1839, s. 94. The most powerful productive faculty in nature is that manifested in the Vorticellae. Estimations of the greatest possible development of masses will be found in Chrenberg's great work 'Die Infusionsthierchen als volkommne Organismen', 1838, s. xiii., xix., and 244. "The Milky Way of these organisms comprises the genera Monas, Vibrio, Bacterium, and Bodo." The universality of life is so profusely distributed throughout the whole of nature, that the smaller Infusoria live as parasites on the larger, and are themselves inhabited by others, s. 194, 211, and 512.

The minutest of the Infusoria, the Monadidae, have a diameter which does not exceed 1/3000th of a line, and yet these silicious-shelled organisms form in humid districts subterranean strata of many fathoms in depth.

The strong and beneficial influence exercised on the feelings of mankind by the consideration of the diffusion of life, throughout the realms of nature is common to every zone, but the impression thus produced is most powerful in the equatorial regions, in the land of palms, bamboos, and arborescent ferns, where the ground rises from the shore of seas rich in mollusca and corals to the limits of perpetual snow. The local distribution of plants embraces almost all heights and all depths. Organic forms not only descend into the interior of the earth, where the industry of the miner has laid open extensive excavations and sprung deep shafts, but I have also found snow-white stalactiitic columns encircled by the delicate web of an Usnea, in caves where meteoric water could alone penetrate through fissures. Podurellae penetrate into the icy crevices of the glaciers on Mount Rosa, the Grindelwald, and the Upper Aar; the Chionaea nivalis (formerly known as Protococcus), exist in the polar snow as well as in that of our high mountains. The redness assumed by the snow after lying on the ground for soome time was known to Aristotle, and was probably observed by him on the mountains of Macedonia.*

[footnote] *Aristot., 'Hist. Animal.', v. xix., p. 552, Bekk.

p 345 While, on the loftiest summits of the Alps, only Lecideae, Parmeliae, and Umbilicariae cast their colored but scanty covering over the rocks, exposed by the melted snow, beautiful phanerogamic plants, as the Culcitium rufescens, Sida pinchinchensis, and Saxifraga Boussingaulti, are still found to flourish in the tropical region of the chain of the Andes, at an elevation of more than 15,000 feet. Thermal springs contain small insects (Hydroporus thermalis), Gallionellae, Oscillatoria and Confervae, while their waters bathe the root-fibers of phanerogamic plants. As air and water are aniimated at different temperatures by the presence of vital organisms, so likewise is the interior of the different portions of animal bodies. Animalcules have been found in the blood of the frog and the salmon; according to Nordmann, the fluids in the eyes of fishes are often filled with a worm that lives by suction (Diplostomum), while in the gills of the bleak the same observer has discovered a remarkable double aniimalcule (Diplozoon paradoxum), having a cross-shaped form with two heads and two caudal extremities.

Although the existence of meteoric Infusoria is more than doubtful, it can not be denied that, in the same manner as the pollen of the flowers of the pine is observed every year to fall from the atmosphere, minute infusorial animalcules may likewise be retained for a time in the strata of the air, after having been passively borne up by currents of aqueous vapor.*

[footnote] *Ehrenberg, op. cit., s. xiv., p. 122 and 403. The rapid multiplication of microscopic organisms is, in the case of some (as, for instance, in wheat-eels, wheel-animals, and water-bears or tardigrade animalcules), accompanied by a remarkable tenacity of life. They have been seen to come to life from a state of apparent death after being dried for twenty-eight days in a vacuum with chloride of line and sulphuric acid, and after being exposed to a heat of 248 degrees. See the beautiful experiments of Doyere, in 'Mem. sur les Tardigrades et sur leur propriete de revenir a la vie', 1842, p. 119, 129, 131, 133. Compare, also, Ehrenberg, s. 492-496, on the revival of animalcules that had been dried during a space of many years.

This circumstance merits serious attention in reconsidering the old discussion respecting 'spontaneous generation',* and the p 346 more so, as Ehrenberg, as I have already remarked, has discovered that the nebulous dust or sand which mariners often encounter in the vicinity of the Cape Verd Islands, and even at a distance of 380 geographical miles from the African shore, contains the remains of eighteen species of silicious-shelled polygastric animalcules.

[footnote] *On the supposed "primitive transformation" of organized or unorganized matter into plants and animals, see Ehrenberg, in Poggendorf's 'Annalen der Physik', bd. xxiv., s. 1-48, and also his 'Infusionsthierchen', s. 121, 525, and Joh. Muller, 'Physiologie des Menschen' (4te Aufl., 1844), bd. i., s. 8-17. It appears to me worthy of notice that one of the early fathers of the Church, St. Augustine, in treating of the question how islands may have been covered with new animals and plants after the flood, shows himself in no way disinclined to adope the view of the so-called "spontaneous generation" ('generatio aequivoca, spontanea aut primaria'). "If," says he, "animals have not been brought to remote islands by angels, or perhaps by inhabitants of continents addicted to the chase, they must have been spontaneously produced upon the earth; although here the question certainly arises, to what purpose, then, were animals of all kinds assembled in the ark?" "Si e terra exort" sunt (bestiae) secundum originem primam, quando dixit Deus" 'Producat terra animam vivam!' multo clarius apparet, non tam reparandorum animalium causa, quam figurandarum variarum gentium (?) propter ecclesiae sacramentumin arca fuisse omnia genera, si in insulis quo transire non possent, multa animalia terra produxit." Augustinus, 'De Civitate Dei', lib. xvi., cap. 7: 'Opera, ed. Monach. Ordinis S. Benedicti', t. vii., Venet., 1732, p. 422. Two centuries before the tiime of the Bishop of Hippo, we find, by extracts from Trogus Pompeius, that the 'generatio primaria' was brought forward in connection with the earliest drying up of the ancient world, and of the high table-land of Asia, precisely in the same manner as the terraces of Paradise, in the theory of the great Linnaeus, and in the visionary hypotheses entertained in the eighteenth century regarding the fabled Atlantis: "Quod si omnes quondam terrae submersae profundo fuerunt, profecto editissilimam quamque partem decurrentibus aquis primum detectam; humillimo autem solo eandem aquam diutissime immoratam, et quanto prior quaeque pars terrarum siccata sit, tanto prius animalia generare coepisse. Porro Scythiam adeo editiorem omnibus terris esse ut cuncta flumina ibi nata in Maeotium, tum deinde in Ponticum et Aegyptium mare decurrant." -- Justinus, lib. ii., cap. 1. The erroneous supposition that the land of Scythia is an elevated table-land, is so ancient that we meet with it most clearly expressed in Hippocrates, 'De Aere et Aquis', cap. 6, 96, Coray. "Scythia," says he, "coonsists of high and naked plains, which, without being crowned with mountains, ascend higher and higher toward the north."

Vital organisms, whose relations in space are comprised under the head of the geography of plants and animals, may be considered either according to the difference and relative numbers of the types (their arrangement into genera and species), or according to the number of individuals of each species on a given area. In the mode of life of plants as in that of animals, an important difference is noticed; they either exist in an isolated state, or live in a social condition. Those species of plants which I have termed 'social'* uniformly cover vast extents of land.

[footnote] *Humboldt, 'Aphorismi ex Physiologia Chemica Plantarum', in the 'Flora Fribergensis Subterranea', 1793, p. 178.

Among these we may reckon many of the marine Algae -- Cladoniae and mosses, which extend over the desert steppes of Northern Asia -- grasses, and cacti growing p 347 together like the pipes of an organ -- Avicennim and mangroves in the tropics -- and forests of Coniferae and of birches in the plains of the Baltic and in Siberia. This mode of geographical distribution determines, together with the individual form of the vegetable world, the size and type of leaves and flowers, in fact, the principal physiognomy of the district,* its characteracter being but little, if at all, influenced by the ever-moving forms of animal life, which, by their beauty and diversity, so powerfully affect the feelings of man, whether by exciting the sensations of admiration or horror.

[footnote] *On the physiognomy of plants, see Humboldt, 'Anischten der Natur', bd. ii., s. 1-125.

Agricultural nations increase artificially the predominance of social plants, and thus augment, in many parts of the temperate and northern zones, the natural aspect of uniformity; and while their labors tend to the extirpation of some wild plants, they likewise lead to the cultivation of others, which follow the colonist in his most distant migration. The luxuriant zone of the tropics offers the strongest resistance to these changes in the natural distribution of vegetable forms.

Observers who in short periods of time have passed over vast tracts of land, and ascended lofty mountains, in which climates were ranged, as it were in strata one above another, must have been early impressed by the regularity with which vegetable forms are distributed. The results yielded by their observations furnished the rough materials for a science, to which no name had as yet been given. The same zones of regions of vegetation which, in the sixteenth century, Cardinal Bembo, when a youth,*described on the declivity of Aetna, were observed on Mount Ararat by Tournefort.

[footnote] *Aetna Dialogus.' 'Opuscula', Basil., 1556, p. 53, 54. A very beautiful geography of the plants of Mount AEtna has recently been published by Philippi. See 'Linnaea', 1832, s. 733.

He ingeniously compared the Alpine flora with the flora of plains situated in different latitudes, and was the first to observe the influence exercised in mountainous regions, on the distribution of plants by the elevation of the ground above the level of the sea, and by the distance from the poles in flat countries. Menzel, in an inedited work on the flora of Japan, accidentally made use of the term 'geography of plants'; and the same expression occurs in the fanciful but graceful work of Bernardin de St. Pierre, 'Etudes de la Nature'. A scientific treatment of the subject began, however, only when the geography of plants was intimately associated with the study of the distribution p 348 of heat over the surface of the earth, and when the arrangement of vegetable forms in natural families admitted of a numerical estimate being made of the different forms which increase of decrease as we recede from the equator toward the poles, and of the relations in which, in diffrent parts of the earth, each family stood with reference to the whole mass of phanerogamic indigenous plants of the same region. I consider it a happy circumstance that, at the time during which I devoted my attention almost exclusively to botanical pursuits, I was led by the aspect of the grand and strongly characterized features of tropical scenery to direct my investigations toward these subjects.

The study of the geographical distribution of animals, regarding which Buffon first advanced general, and, in most instances, very correct views, has been considerably aided in its advance by the progress made in modern times in the geography of plants. The curves of the isothermal lines, and more especially those of the isochimenal lines, correspond with the limits which are seldom passed by certain species of plants, and of animals which do not wander far from their fixed habitation either with respect to elevation or latitude.*

[footnote] *[The following valuable remarks by Professor Forbes, on the correspondence existing between the distribution of existing faunas and floras of the British Islands, and the geological changes that have affected their area, will be read with much interest; they have been copied, by the author's permission, from the 'Survey Report', p. 16: "If the view I have put forward respecting the origin of the flora of the British mountains be true -- and every geological and botanical probability, so far as the are is concerned, favors it -- then must we endeavour to find some more plausible cause than any yet shown for the presence of numerous species of plants, and of some animals, on the higher parts of Alpine ranges in Europe and Asia, specifically identical with animals and plants indigenous in the regions very far north, and not found in the intermediate lowlands. Tournefort first remarked and Humboldt, the great organizer of the science of natural history geography, demonstrated, that zones of elevation on mountains correspond to parallels of latitude, the higher with the more northern or southern, as the case might be. It is well known that this correspondence is recognized in the general 'facies' of the flora and fauna, dependent on generic identities. But when announcing and illustrating the law that climatal zones of animal and vegetable life are mutually repeated or represented by elevation and latitude, naturalists have not hitherto sufficiently (if at all) distinguished between the evidence of that law, as exhibited by 'representative species' and by 'identical'. In reality, the former essentially depend on the law, the latter being an 'accident' not necessarily dependent upon it, and which has hitherto not been accounted for. In the case of the Alpine flora of Britain, the evidence of the activity of the law, and the influence of the accident, are inseparable, the law being maintained by a transported flora, for the transmission of which I have shown we can not account by an appeal to unquestionable geological events. In the case of the Alps and Carpathians, and some other mountain ranges, we find the law maintained partly by a representative flora, special in its region, i.e., by specific centers of their own, and partly by an assemblage more or less limited in the several ranges of identical species, these latter in several cases so numerous that ordinary modes of transportation now in action can no more account for their presence than they can for the presence of a Norwegian flora on the British mountains. Now I am prepared to maintain that the same means which introduced a sub-Arctic (now mmountain) flora into Britain, acting at the same epoch, originated the identity, as far as it goes, of the Alpine floras of middle Europe and Central Asia; for, now that we know the vast area swept by the glacial sea, including almost the whole of Central and Northern Europe, and belted by land, since greatly uplifted, which then presented to the water's edge those climatal lconditions for which a sub-Arctic flora -- destined to become Alpine -- was specially organized, the difficulty of deriving such a flora from its paarent north, and of diffusing it over the snowy hills bounding this glacial ocean, vanishes, and the presence of identical species at such distant pooints remain no longer a mystery. Moreover, when we consider that conditions during the epoch referred to, the undoubted evidences of Continental observers, on the boounds of Asia by Sir Roderick Murchison, in America by Mr. Lyell, Mr. Logan, Captain Bayfield, and others, and that the botanical (and zoological as well) region, essentially northern and Alpine, designated by Professor Schouw that 'of saxifrages and mosses,' and first in his classification, exists now only on the flanks of the great area which suffered such conditions; and that, though similar conditions reappear, the relationship of Alpine and Arctic vegetation in the southern hemisphere, with that in the northern, is entirely maintained by 'representative', and not by identical species (the general truth of my explanation of Alpine floras, including identical species, becomes so strong, that the view proposed acquires fair claims to be ranked as a theory, and not considered merely a convenient or bold hypothesis."] -- Tr.

The p 349 elk, for instance, lives in the Scandinavian peninsula, almost ten degrees further north than in the interior of Siberia, where the line of equal winter temperature is so remarkably concave. Plants migrate in the germ; and, in the case of many species, the seeds are furnished with organs adapting them to be conveyed to a distace through the air. When once they have taken root, they become dependent on the soil and on the strata of air surrounding them. Animals, on the contrary, can at pleasure migrate from the equator toward the poles; and this they can more especially doo where the isothermal lines are much inflected, and where hot summers succeed a great degree of winter cold. The royal tiger, which in no respect differs from the Bengal species, penetrates every summer into p 350 the north of Asia as far as the latitudes of Berlin and Hamburg, a fact of which Ehrenberg and myself have spoken in other works.*

[footnote] *Ehrenberg, in the 'Annales des Sciences Naturelles', t. xxi., p. 387, 412; Humboldt, 'Asie Centrale', t. i., p. 339-342, and t. iii., p. 96-101.

The grouping or association of diffrent vegetable species, to which we are accustomed to apply the term 'Floras', do not appear to me, from what I have observed in different portions of the earth's surface, to manifest such a predominance of individual families as to justify us in marking the geographical distinctions between the regions of the Umbellatae, of the Solidaginae, of the Labiatae, or the Scitamineae. With reference to this subject, my views differ from those of several of my friends, who rank among the most distinguished of the botanists of Germany. The character of the floras of the elevated plateaux of Mexico, New Granada, and Quito, of European Russia, and of Northern Asia, consists, in my opinion, not so much in the relatively larger number of the species presented by one or two natural families, as in the more complicated relations of the coexistence of many families, and in the relative numerical value of their species. The Gramineae and the Cyperaceae undoubtedly predominate in meadow lands and stppes, as do Coniferae, Cupuliferae, and Betulineae in our northern woods; but this predominance of certain forms is only apparent, and owing to the aspect imparted by the social plants. The north of Europe, and that portion of Siberia which is situated to the north of the Altai Mountains, have no greater right to the appellation of a region of Gramineae and Coniferae than have the boundless llanos between the Orinoco and the mountain chain of Caraccas, or the pine forests of Mexico. It is the coexistence of forms which may partially replace each other, and their relative numbers and association, which give rise either to the general impression of luxuriance and diversity, or of poverty and uniformity in the contemplation of the vegetable world.

In this fragmentary sketch of the phenomena of organization, I have ascended from the simplest cellI -- the first manifestation of life -- progressively to higher structures. "The p 351 association of mucous granules constitutes a definitely-formed cytoblase, around which a vesicular membrane forms ia closed well," this cell being either produced from another pre-existing cell,** or being due to a cellular formation, which, as in the case of the fermentation-fungus, is concealed in the obscurity of some unknown chemical process.***

[footnote] *Schleiden, 'Ueber die Entwicklungsweise der Pflanzenzellen', in Muller's 'Archiv fur Anatomie und Physiologie', 1838, s. 137-176; also his 'Grundzuge der wissenschaftlichen Botanik', th. i., s. 191, and th. ii., s 11. Schwann, 'Mikroscopische Untersucungen uber die Uebereinstimmung in der Struktur und dem Wachsthum der Thiere und Pflanzen', 1839, s. 45, 220. Compare also, on similar propagation, Joh. Muller 'Physiologie des Menschen', 1840, th. ii., s. 614.

[footnote] **Schleiden, 'Grundzuge der wissenschaftlichen Botanik', 1842, th. i., s. 192-197.

[footnote] ***[On cellular formation, see Henfrey's 'Outlines of Structural and Physiological Botany', op. cit., p. 16-22.] -- Tr.

But in a work like the present we can venture on no more than an allusion to the mysteries that involve the question of modes of origin; the geography of animal and vegetable organisms must limit itself to the consideration of germs already developed, of their haabitation and transplantation, either by voluntary or involuntary migrations, their numerical relation, and their distribution over the surface of the earth.

The general picture of nature which I have endeavored to delineate would be incomplete if I did not venture to trace a few of the most marked features of the human race, considered with reference to physical gradations -- to the geographical distribution of contemporaneous types -- to the influence exercised upon man by the forces of nature, and the reciprocal, although weaker action which he in his turn exercises on these natural forces. Dependent, although in a lesser degree than plants and animals, on the soil, and on the meteorological processes of the atmosphere with which he is surroounded -- escaping more readily from the control of natural forces, by

## activity of mind and the advance of intellectual cultivation, no less than

by his wonderful capacity of adapting himself to all climates -- man every where becomes most essentially associated with terrestrial life. It is by these relations that the obscure and much-contested problem of the possibility of one common descent enters into the sphere embraced by a general physical cosmography. The investigation of this problem will impart a nobler, and, if I may so express myself, more purely human interest to the closing pages of this section of my work.

The vast domain of language, in whose varied structure we see mysteriously reflected the destinies of nations, is most intimately associated with the affinity of races; and what even slight differences of races may effect is strikingly manifested in the history of the Hellenic nations in the zenith of their intellectual cultivation. The most important questions of the civilization of mankind are connected with the ideas of races, p 352 community of language, and adherence to one original direction of the intellectual and moral faculties.

As long as attention was directed solely to the extremes in varieties of color and of form, and to the vividness of the first impression of the senses, the observer was naturally disposed to regard races rather as originally different species than as mere varieties. The permanence of certain types* in the midst of the most hostile influences, especially of climate, appeared to favor such a view, notwithstanding the shortness of the interval of time from which the historical evidence was derived.

[footnote] *Tacitus, in his speculations on the inhabitants of Britain ('Agricola', cap. ii.), distinguishes with much judgment between that which may be owing to the local climatic relations, and that which, in the immigrating races, may be owing to the unchangeable influence of a hereditary and transmitted type. "Britanniam qui mortales initio coluerunt, indigenae an advecti, ut inter barbaros, parum coompertum. Habitus corporis varii, alque ex eo argumenta; namque rutilae Caledoniam habitantium comae, magni artus Germanicam originem adseverant. Silu ram colorati vultus et torti plerumque crines, et posita contra Hispania, Iberos veteres trajecisse, easque cedes occupasse fidem faciunt: proximi Gallis, et similes sunt: seu durante originis vi; seu procurrentibus in diversa terris, positio coeli corporibus habitum dedit." Regarding the persistency of types of conformation in the hot and cold regions of the earth, and in the mountainous districts of the New Continent, see my 'Relation Historique', t. i., p. 498, 503, and t. ii., p. 572, 574.

In my opinion, however, more powerful reasons can be advanced in support of the theory of the unity of the human race, as, for instance, in the many intermediate gradations* in the color of the skin and in the form of the skull, which have been made known to us in recent times by the rapid progress of geographical knowledge -- the analogies presented by the varieties in the species of many wild and domesticated animals -- and the more correct observations collected regarding the limits of fecundity in hybrids.**

[footnote] On the American races generally, see the magnificent work of Samuel George Morton, entitled 'Crania Americana', 1839, p. 62, 86; and on the skulls brought by Pentland from the highlands ot titicaca, see the 'Dublin Journal of Medical and Chemical Science', vol. v., 1834, p. 475; also Alcide d'Orbigny, 'L'homme Americain considere sous ses rapports Physiol. et Mor.', 1839, p. 221; and the work by Prince Maximilian of Wied, which is well worthy of notice for the admirable ethnographical remarks in which it abounds, entitled 'Reise in das Innere von Nordamerika' (1839).

[footnote] ** Rudolph Wagner, 'Ueber Blendlinge und Bastarderzeugung', in his notes to the German translation of Prichard's 'Physical History of Mankind', vol. i., p. 138-150.

The greater number of the contrasts which were formerly supposed to exist, have disappeared before the laborious researches of Tiedemann on the brain of negroes and of Europeans, and the anatomical investigations p 353 of Vrolik and Weber on the form of the pelvis. On comparing the dark-colored African nations, on whose physical history the admirable work of Prichard has thrown so much light, with the races inhabiting the islands of the South-Indian and West-Australian archipelago, and with the Papuas and Alfourous (Haroforas, Endamenes), we see that a black skin, woolly hair, and a negro-like cast of countenance are not necessarily connected together.*

[footnote] *Prichard, op. cit., vol. ii., p. 324.

So long as only a small portion of the earth was known to the Western nations, partial views necessarily predominated, and tropical heat and a black skin consequently appeared inseparable. "The Ethiopians," said the ancient tragic poet Theodectes of Phaselis,* "are colored by the near sun-god in his course with a sooty luster, and their hair is dried and crisped with the heat of his rays."

[footnote] *Onesicritus, in Strabo, xv., p. 690, 695, Casaub. Welcker, 'Griechische Tragodien', abth. iii., s. 1078, conjectures that the verses of Theodectes, cited by Strabo, are taken from a list tragedy, which probably bore the title of "Memnon."

The campaigns of Alexander, which gave rise to so many new ideas regarding physical geography, likewise first excited a discussion on the problematical influence of climate on races. "Families of animals and plants," writes one of the greatest anatomists of the day, Johannes Muller, in his noble and comprehensive work, 'Physiologie des Menschen', "undergo, within certain limitations peculiar to the different races and species, various modifications in their distribution over the surface of the earth, propagating these variations as organic types of species.*

[footnote] *[In illustration of this, the conclusions of Professor Edward Forbes respecting the origin and diffusion of the British flora may be cited. See the 'Survey Memoir' already quoted, 'On the Connection between the Distribution of the existing Fauna and Flora of the British Islands, etc.', p. 64. "1. The flora and fauna, terrestrial and marine, of the British islands and seas, have originated, so far as that area is concerned, since the melocene epoch. 2. The assemblages of animals and plants compositing that fauna and flora did not appear in the area they now inhabit simultaneously, but at several distinct points in time. 3. Both the fauna and flora of the British islands and seas are composed partly of species which, either permanently or for a time, appeared in that area before the glacial epoch; partly of such as inhabited it during that epoch; and in great part of those which did not appear there until afterward, and whose appearance on the earth was coeval with the elevation of the bed of the glacial sea and the consequent climatal changes. 4. The greater part of the terrestrial animals and flowering plants now inhabiting the British islands are members of specific centers beyond their area, and have migrated to it over continuous land before, during, or after the glacial epoch. 5. The climatal conditions of the area under discussion, and north, east, and west of it, were severer during the glacial epoch, when a great part of the space now occupied by the British isles was under water, than they are now or were before; but there is good reason to believe that, so far from those conditions having continued severe, or having gradually diminished in severity southward of Britain, the cold region of the glacial epoch came directly into contact with a region of more southern and thermal character than that in which the most southern beds of glacial drift are now to be met with. 6. This state of things did not materially differ from that now existing, under corresponding latitudes, in the North American, Atlantic, and Arctic seas, and on their bounding shores. 7. The Alpine floras of Europe and Asia, so far as they are identical with the flora of the Arctic and sub-Arctic zones of the Old World, are fragments of a flora which was diffused from the north, either by means of transport not now in action on the temperate coasts of Europe, or over continuous land which no longer exists. The deep sea fauna is in like manner a fragment of the general glacial fauna. 8. The floras of the islands of the Atlantic region, between the Gulf-weed Bank and the Old World, are fragments of the Great Mediterranean flora, anciently diffused over a land consistuted out of the upheaval and never again subjerged bed of the (shallow) Meiocene Sea. This great flora, in the epoch anterior to, and probably, in part, during the glacial period, had a greater extension northward than it now presents. 9. The termination of the glacial epoch in Europe was marked by a recession of an Arctic fauna and flora northward, and of a fauna and flora of the Mediterranean type southward; and in the interspace thus produced there appeared on land the Germanic fauna and flora, and in the sea that fauna termed Celtic. 10. The causes which thus preceded the appearance of a new assemblage of organized beings were the destruction of many species of animals, and probably also of plants, either forms of extremely local distribution, or such as were not capable of enduring many changes of conditions -- species, in short, with very limited capacity for horizontal or vertical diffusion. 11. All the changes before, during, and after the glacial epoch appear to have been gradual, and not sudden, so that no marked line of demarkation can be drawn between the creatures inhabiting the same element and the same locality during two proximate periods."] -- Tr.

The different races of mankind are forms of one sole species, by the union of two of whose members descendants are propagated. They are not different species of a genus, since in that case their hybrid descendants would remain unfruitful. But whether the human races have descended from several primitive races of men, or from one alone, is a question that can not be determined from experience."*

[footnote] *Joh. Muller, 'Physiologie des Menschen', bd. ii., s. 768.

Geographical investigations regarding the ancient 'seat', the so-called 'cradle of the human race', are not devoid of a mythical p 355 character. "We do not know," says Wilhelm von Humboldt, in an unpublished work 'On the Varieties of Languages and Nations', "either from history or from authentic tradition, any period of time in which the human race has not been divided into social groups. Whether the gregarious condition was original, or of subsequent occurrence, we have no historic evidence to show. The separate mythical relations found to exist independently of one another in different parts of the earth, appear to refute the first hypothesis, and concur in ascribing the generation of the whole human race to the union of one pair. The general prevalence of this myth has cause it to be regarded as a traditionary record transmitted from the primitive man to his descendants. But this very circumstance seems rather to prove that it has no historical foundation, but has simply arisen from an identity in the mode of intellectual conception, which has every where led man to adopt the same conclusion regarding identical phenomena; in the same manner as many myths have doubtlessly arisen, not from any historical connection existing between them, but rather from an identity in human thought and imagination. Another evidence in favor of the purely mythical nature of this belief is afforded by the fact that the first origin of mankind -- a phenomenon which is wholly beyond the sphere of experience -- is explained in perfect conformity with existing views, being considered on the principle of the colonization of some desert island or remote mountainous valley at a period when mankind had already existed for thousands of years. It is in vain that we direct our thoughts to the solution of the great problem of the first origin, since man is too intimately associated with his own race and with the relations of time to conceive of the existence of an individual independently of a preceding generation and age. A solution of those difficult questions, which can not be determined by inductive reasoning or by experience -- whether the belief in this presumed traditional condition be actually based on historical evidence, or whether mankind inhabited the earth in gregarious associations from the origin of the race -- can not, therefore, be determined from philological data, and yet its elucidation ought not to be sought from other sources."

The distribution of mankind is therefore only a distribution into 'varieties', which are commonly designated by the somewhat indefinite term 'races'. As in the vegetable kingdom, and in the natural history of birds and fishes, a classification into many small families is based on a surer foundation than p 356 where large sections are separated into a few but large divisions; so it also appears to me, that in the determination of races a preference should be given to the establishment of small families of nations. Whether we adopt the old classification of my master, Blumenbach, and admit 'five' races (the Caucasian, Mongolian, American, Ethiopian, and Malayan), or that of Prichard, into 'seven races'* (the Iranian, Turanian, American, Hottentots and Bushmen, Negroes, Papuas, and Alfourons), we fail to recognize any typical sharpness of definition, or any general or well-established principle in the division of these groups.

[footnote] *Prichard, op. cit., vol. i., p. 247.

The extremes of form and color are certainly separated, but without regard to the races, which can not be included in any of these classes, and which have been alternately termed Scythian and Allophyllic. Iranian is certainly a less objectionable term for the European nations than Caucasian; but it may be maintained generally that geographical denominations are very vague when used to express the points of departure of races, more especially where the country which has given its name to the race, as, for instance, Turan (Mawerannahr), has been inhabited at different periods* by Indo-Germanic and Finnish, and not by Mongolian tribes.

[footnote] *The late arrival of the Turkish and Mongolian tribes on the Oxus and on the Kirghis Steppes is opposed to the hypothesis of Niebuhr, according to which the Scythians of Herodotus and Hippocrates were Mongolians. It seems far more probable that the Scythians (Scoloti) should be referred to the Indo-Germanic Massagetae (Alani). The Mongolian, true Tartars (the latter term was afterward falsely given to purely Turkish tribes in Russia and Siberia), were settled, at that period, far in the eastern part of Asia. See my 'Asie Centrale', t. i., p. 239, 400; 'Examen Critique de l'Histoire de la Geogr.', th. ii., p. 320. A distinguished philologist, Professor Buschmann, calls attention to the circumstance that the poet Firdousi, in his half-mythical prefatory remarks in the 'Schahnameh', mentions "a fortress of the Alani" on the sea-shore, in which Selm took refuge, this prince being the eldest son of the King Feridun, who in all probability lived two hundred years before Cyrus. The Kirghis of the Scythian steppe were originally a Finnish tribe; their three hordes probably constitute in the present day the most numerous nomadic nation, and their tribe dwelt, in the sixteenth century, in the same steppe in which I have myself seen them. The Byzantine Menander (p. 380-382, ed. Nieb.) expressly states that the Chacan of the Turks (Thu-Khiu), in 569, made a present of a Kirghis slave to Zemarchus, the embassador of ustinish II.; he terms her a [Greek word]; and we find in Abulgasi ('Historia Mongolorum et Tatarorum') that the Kirghis are called Kirkiz. Similarity of manners, where the nature of the country determines the principal characteristics, is a very uncertain evidence of identity of race. The life of the steppes produces among the Turks (Ti Tukiu), the Baschkirs (Fins), the Kirghis, the Torgodi and Dsungari (Mongolians), the same habits of nomadic life, and the same use of felt tents, carried on wagons and pitched among herds of cattle.

p 357 Languages, as intellectual creations of man, and as closely interwoven with the development of mind, are, independently of the 'national' form which they exhibit, of the greatest importance in the recognition of similarities or differences in races. This importance is especially owing to the clew which a community of descent affords in treading that mysterious labyrinth in which the connection of physical powers and intellectual forces manifests itself in a thousand different forms. The brilliant progress made within the last half century, in Germany, in philosophical philology, has greatly facilitated our investigations into the 'national' character* of languages and the influence exercised by descent.

[footnote] *Wilhelm von Humboldt, 'Ueber die Verschiedenheit der menschlichen Sprachbaues', in his great work 'Ueber die Kawi-Sprache auf der Insel Java', bd. i., s. xxi., xlviii., and ccxiv.

But here, as in all domains of ideal speculation, the dangers of deception are closely linked to the rich and certain profit to be derived.

Positive ethnographical studies, based on a thorough knowledge of history, teach us that much caution should be applied in entering into these comparisons of nations, and of the languages employed by them at certain epochs. Subjection, long association, the influence of a foreign religion, the blending of races, even when only including a small number of the more influential and cultivated of the immigrating tribes, have produced, in both continents, similarly recurring phenomena; as, for instance, in introducing totally different families of languages among one and the same race, and idioms, having one common root, among nations of the most different origin. Great Asiatic conquerors have exercised the most powerful influence on phenomena of this kind.

But language is a part and parcel of the history of the development of mind; and however happily the human intellect, under the most dissimilar physical conditions, may unfettered pursue a self-chosen track, and strive to free itself from the dominion of terrestrial influences, this emancipation is never perfect. There ever remains, in the natural capacities of the mind, a trace of something that has been derived from the influences of race or of climate, whether they be associated with a land gladdened by cloudless azure skies, or with the vapory atmosphere of an insular region. As, therefore, richness and grace of language are unfolded from the most luxuriant p 358 depths of thought, we have been unwilling wholly to disregard the bond which so closely links together the physical world with the sphere of intellect and of the feelings by depriving this general picture of nature of those brighter lights and tints which may be borrowed from considerations, however slightly indicated, of the relations existing between races and languages.

While we maintain the unity of the human species, we at the same time repel the depressing assumption of superior and inferior races of men.*

[footnote] *The very cheerless, and, in recent times, too often discussed doctrine of the unequal rights of men to freedom, and of slavery as an institution in conformity with nature, is unhappily found most systematically developed in Aristotle's 'Politica', i., 3, 5, 6.

There are nations more susceptible of cultivation, more highly civilized, more enobled by mental cultivation than others, but none in themselves nobler than others. All are in like degree designed for freedom; a freedom which, in the ruder conditions of society, belongs only to the individual, but which, in social states enjoying political institutions, appertains as a right to the whole body of the community. "If we would indicate an idea which, throughout the whole course of history, has ever more and more widely extended its empire, or which, more than any other, testifies to the much-contested and still more decidedly misunderstood perfectibility of the whole human race, it is that of establishing our common humanity -- of striving to remove the barriers which prejudice and limited views of every kind have erected among men, and to treat all mankind, without reference to religion, nation, or color, as one fraternity, one great community, fitted for the attainment of one object, the unrestrained development of the physical powers. This is the ultimate and highest aim of society, identical with the direction implanted by nature in the mind of man toward the indefinite extension of his existence. He regards the earth in all its limits, and the heavens as far as his eye can scan their bright and starry depths, as inwardly his own, given to him as the objects of his contemplation, and as a field for the development of his energies. Even the child longs to pass the hills or the seas which inclose his narrow home; yet, when his eager steps have borne him beyond those limits, he pines, like the plant, for his native soil; and it is by this touching and beautiful attribute of man -- this longing for that which is unknown, and this fond remembrance of that which is lost -- that he is spared from an exclusive attachment to the present. p 359 Thus deeply rooted in the innermost nature of man, and even enjoined upon him by his highest tendencies, the recognition of the bond of humanity becomes one of the noblest leading principles in the history of mankind."*

[footnote] *Wilhelm von Humboldt, 'Ueber die Kawi-Sprache', bd. iii., s. 426. I subjoin the following extract from this work: "The impetuous conquests of Alexander, the more politic and premeditated extension of territory made by the Romans, the wild and cruel incursions of the Mexicans, and the despotic acquisitions of the incas, have in both hemispheres contributed to put an end to the separate existence of many tribes as independent nations, and tended at the same time to establish more extended international amalgamation. Men of great and strong minds, as well as whole nations, acted under the influence of one idea, the purity of which was, however, utterly unknown to them. It was Christianity which first promulgated the truth of its exalted charity, although the seed sown yielded but a slow and scanty harvest. Before the religion of Christ manifested its form, its existence was only revealed by a faint foreshadowing presentiment. In recent times, the idea of civilization has acquired additional intensity, and has given rise to a desire of extending more widely the relations of national intercourse and of intellectual cultivation; even selfishness begins to learn that by such a course its interests will be better served than by violent and forced isolation. Language more than any other attribute of mankind, binds together the whole human race. By its idiomatic properties it certainly seems to separate nations, but the reciprocal understanding of foreign languages connects men together on the other hand without injuring individual national characteristics."

With these words, which draw their charm from the depths of feeling, let a brother be permitted to close this general description of the natural phenomena of the universe. From the remotest nebulae and from the revolving double stars, we have descended to the minutest organisms of animal creation, whether manifested in the depths of ocean or on the surface of our globe, and to the delicate vegetable germs which clothe the naked declivity of the ice-crowned mountain summit; and here we have been able to arrange these phenomena according to partially known laws; but other laws of a more mysterious nature rule the higher spheres of the organic world, in which is comprised the human species in all its varied conformation, its creative intellectual power, and the languages to which it has given existence. A physical delineation of nature terminates at the point where the sphere of intellect begins, and a new world of mind is opened to our view. It marks the limit, but does not pass it.

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p 361

ADDITIONAL NOTES

TO THE PRESENT EDITION. MARCH, 1849.

__________

GIGANTIC BIRDS OF NEW ZEALAND. -- Vol. i., p. 287. An extensive and highly interesting collection of bones, referrible to several species of the 'Moa' (Dinornis of Owen), and to three or four other genera of birds, formed by Mr. Walter Mantell, of Wellington, New Zealand, has recently arrived in England, and is now deposited in the British Museum. This series consists of between 700 and 800 speciments, belonging to different parts of the skeletons of many individuals of various sizes and ages. Some of the largest vertebrae, tibiae, and femora equal in magnitude the most gigantic previously known, while others are not larger than the corresponding bones of the living apteryx. Among these relics are the 'skulls' and 'mandibles' of two genera, the 'Dinornis' and 'Palapteryx'; and of an extinct genus, 'Notornis', allied to the 'Rallidae'; and the mandibles of a species of 'Nestor', a genus of nocturnal owl-like parrots, of which only two living species are known.*

[footnote] *See Professor Owen's Memoir on these fossil remains, in 'Zoological Transactions', 1848.

These osseous remains are in a very different state of preservation from any previously received from New Zealand; they are light and porous, and of a light fawn-color; the most delicate processes are entire, and the articulating surfaces smooth and uninjured; 'fragments of egg-shells', and even the bony rings of the trachea and air tubes, are preserved'.

The bones were dug up by Mr. Walter Mantell from a bed of marly sand, containing magnetic iron, crystals of hornblende and augite, and the detritus of augitic rocks and earthy volcanic tuff. The sand had filled up all the cavities and cancelli, but was in no instance consolidated or aggregated together; it was, therefore, easily removed by a soft brush, and the bones perfectly cleared without injury.

The spot whence these precious relics of the colossal birds that once inhabited the islands of New Zealand were obtained, is a flat tract of land, near the embouchure of a river, named Waingongoro, not far from Wanganui, which has its rise in the volcanic regions of Mount Egmont. The natives affirm that this level tract was one of the places first dwelt upon by their remote ancestors; and this tradition is corroborated by the existence of numerous heaps and pits of ashes and charred bones indicating ancient fires, long burning on the same spot. In these fire-heaps Mr. Mantell found burned bones of 'men, moas', and 'dogs'.

The fragments of egg-shells, imbedded in the ossiferous deposits, had escaped the notice of all previous naturalists. They are, unfortunately, very small portions, the largest being only four inches long, but they afford a chord by which to estimate the size of the original. Mr. Mantell observes that the egg of the Moa must have been so large that a hat would form a good egg-cup for it. These relics evidently belong to two or more species, perhaps genera. In some examples the external p 362 surface is smooth; in others it is marked with short intercepted linear grooves, resembling the eggs of some of the Struthiouidae, but distinct from all known recent types. In this valuable collection only one bone of a mammal has been detected, namely, 'the femur of a dog'.

An interesting memoir on the probable geological position and age of the ornithic bone deposits of New Zealand, by Dr. Mantell, based on the observations of his enterprising son, it published in the Quarterly Journal of the Geological Society of London (1848). It appears that in many instances the bones are imbedded in sand and clay, which lie beneath a thick deposit of volcanic detritus, and rest on an argillaceous stratum abounding in marine shells. The specimens found in the rivers and streams have been washed out of their banks by the currents which now flow through channels from ten to thirty feet deep, formed in the more ancient alluvial soil. Dr. Mantell concludes that the islands of New Zealand were densely peopled at a period geologically recent, though historically remote, by tribes of gigantic brevi-pennate birds allied to the ostrich tribe, all, or almost all, of species and genera now extinct; and that, subsequently to the formation of the most ancient ornithic deposit, the sea-coast has been elevated from fifty to one hundred feet above its original level; hence the terraces of shingle and loam which now skirt the maritime districts. The existing rivers and mountain torrents flow in deep gulleys which they have eroded in the course of centuries in these pleistocene strata, in like manner as the river courses of Auvergne, in Central France, are excavated in the mammiferous tertiary deposits of that country. The last of the gigantic birds were probably exterminated, like the dodo, by human agency: some small species allied to the apteryx may possibly be met with in the unexplored parts of the middle island.

THE DODO. -- A most valuable and highly interesting history of the dodo and its kindred* has recently appeared in which the history, affinities, and osteology of the 'Dodo, Solitaire', and other extinct birds of the islands Mauritius, Rodriguez, and Bourbon are admirably elucidated by H. G. Strickland (of Oxford), and Dr. G. A. Melville.

[footnote] *'The Dodo and its Kindred'. By Messrs. Strickland and Melville. 1 vol. 4to. with numerous plates. Reeves, London, 1848.

The historical part is by the former, the osteological and physiological portion by the latter eminent anatomist. We would earnestly recommend the reader interested in the most perfect history that has ever appeared, of the extinction of a race of large animals, of which thousands existed but three centuries ago, to refer to the original work. We have only space enough to state that the authors have proved, upon the most incontrovertible evidence, that the dodo was neither a vulture, ostrich, nor galline, as previously anatomists supposed, but a 'frugiverous pigeon'.

This section from pp 363-379 of:

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1 by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1 --------------------------------------------------

p 363 INDEX TO VOL. I. -------------------

ABICH, Hermana, structural relations of volcanic rocks, 234.

Acosta, Joseph de, Historia Natural de las Indias, 66, 193.

Adams, Mr., planet Neptune. See note by Translator, 90, 91.

Aegos Potamos, on the aerolite of, 117, 122.

Aelian on Mount Aetna, 227.

Aerolites (shooting stars, meteors, meteoric stones, fire-balls, etc), general description of, 111-137; physical character, 112-123; dates of remarkable falls, 114, 115; their planetary velocity, 116-120; ideas of the ancients on, 115, 116; November and August periodic falls of shooting stars, 118-120, 124-126; their direction from one point in the heavens, 120; altitude, 120; orbit, 127; Chinese notices of, 128; media of communication with other planetary bodies, 136; their essential difference from comets, 137; specific weights, 116, 117; large meteoric stones on record, 117; chemical elements, 117, 129-131; crust, 129, 130; deaths occasioned by, 135.

Aeschylus, "Prometheus Delivered," 115.

Aetna, Mount, its elevation, 28, 229; supposed extinction by the ancients, 227; its eruptions from lateral fissures, 229; similarity of its zones of vegetation to those of Ararat, 347.

Agassiz, Researches on Fossil Fishes, 46, 273-277.

Alexander, influence of his campaigns on physical science, 353.

Alps, the, elevation of, 28, 29.

Amber, researches on its vegetable origin, 284; Goppert on the amber-tree of the ancient world (Pinites succifer), 283.

Ampere, Andre Marie, 58, 193, 236.

Anaxagoras on aerolites, 122; on the surrounding ether, 134.

Andes, the, their altitude, etc. See Cordilleras.

Anghiera, Peter Martyr de, remarked that the palmeta and pineta were found associated together, 282, 283; first recognized (1510) that the limit of perpetual snow continues to ascend as we approach the equator, 329.

Animal life, its universality, 342-345; as viewed with microscopic powers of vision, 341-346; rapid propagation and tenacity of life in animalcules, 344-346; geography of, 341-346.

Anning, Miss Mary, discovery of the ink bag of the sepia, and of coprolites of fish, in the lias of Lyme Regis, 271, 272.

Austed's, D. R., "Ancient World." See notes by Translator, 271, 272, 274, 281, 287.

Aplan, Peter, on comets, 101.

Apollonius Myndius, described the paths of comets, 103.

Arago, his ocular micrometer, 39; chromatic polarization, 52; optical considerations, 85; on comets, 99-106; polarization experiments on the light of comets, 105; aerolites, 114; on the November fall of meteors, 124; zodiacal light, 143; motion of the solar system, 146, 147; on the increase of heat at increasing depths, 173, 174; magnetism of rotation, 179, 180; horary observations of declination at Paris compared with simultaneous perturbations at Kasan, 191; discovery of the influence of magnetic storms on the course of the needle, 194, 195; on south polar bands, 198; on terrestrial light, 202; phenomenon of supplementary rainbows, 220; observed the deepest Artesian wells to be the warmest, 223; explanation of the absence of a refrigeration of temperature in the lower strata of the Mediterranean, 303; observations on the mean annual quantity of rain in Paris, 333; his investigations on the evolution of lightning, 337.

Argelander on the comet of 1811, 109; on the motion of the solar system, 146, 149; on the light of the Aurora, 195, 196.

Aristarchus of Samos, the pioneer of the Copernican system, 65.

Aristotle, 65; his definition of Cosmos, 69; use of the term history, 75; on comets, 103, 104; on the Ligyan field of stones, 115; aerolites, 122; on the stone of Aegos Potamos, 135; aware that noises sometimes existed without earthquakes, 209; his account of the upheavals of islands of eruption, 241; "spontaneous motion," 341; noticed the redness assumed by long fallen snow, 344.

Artesian wells, temperature of, 174, 223.

Astronomy, results of, 38-40; phenomena of physical astronomy, 43, 44.

Atmosphere, the general description of, 311, 316; its composition and admixture, 312; variation of pressure, 313-317; climatic distribution of heat, 313, 317-328; distribution of humidity, 313, 328, 334; electric condition, 314, 335-338.

p 363 August, his psychometer, 332.

Augustine, St., his views on spontaneous generation, 345, 346.

Aurora Borealis, general description of 193-202; origin and course, 195, 196; altitude, 199; brilliancy coincident with the fall of shooting stars, 126, 127; whether attended with crackling sound, 199, 200; intensity of the light, 201.

Bacon, Lord, 53, 58; Novum Organon, 290.

Baer, Von, 337.

Barometer, the increase of its height attended by a depression of the level of the sea, 298; horary oscillations of, 314, 315

Batten, Mr., letter on the snow-line of the two sides of the Himalayas, 331, 332.

Beaufort, Capt., observed the emissions of inflammable gas on the Caramanian coast, as described by Pliny, 223. See also, note by Translator, 223.

Beaumont, Elie de, on the uplifting of mountain chains, 51, 300; influence of the rocks of melaphyre and serpentine, on pendulum experiments, 167; conjectures on the quartz strata of the Col de la Poissoniere, 266.

Baccaria, observation of steady luminous appearance in the clouds, 202; of lightning clouds, unaccompanied by thunder or indication of storm, 337.

Beechey, Capt., 97; observations on the temperature and density of the water of the ocean under different zones of longitude and latitude, 306.

Bembo, Cardinal, his observations on the eruptions of Mount Aetna, 229; theory of the necessity of the proximity of volcanoes to the sea, 243; vegetation on the declivity of Aetna, 347.

Berard, Capt., shooting stars, 119.

Berton, Count, his barometrical measurements of the Dead Sea, 296.

Berzelins on the chemical elements of aerolites, 130, 131.

Benzenberg on meteors and shooting stars, 119, 120; their periodic return in Autgust, 125.

Bessel's theory on the oscillations of the pendulum, 44; pendulum experiments, 64; on the parallax of 61 Cygni, 88; on Halley's comet, 102, 103, 104; on the ascent of shooting stars, 123; on their partial visibility, 128; velocity of the sun's translatory motion, 145; mass of the star 61 Cygni, 148; parallaxes and distances of fixed stars, 153; comparison of measurements of degrees, 165, 166.

Biot on the phenomenon of twilight, 118; on the zodical light, 141; pendulum experiments at Bordeaux, 170.

Biot, Edward, Chinese observations of comets, 101, 109; of aerolites, 128.

Bischof on the interior heat of the globe, 217, 219, 235, 244, 294.

Blumenbach, his classification of the races of men, 356.

Bockh, origin of the ancient myth of the Nemean lunar lion, 134, 135.

Boguslawski, falls of shooting stars, 119, 128.

Bonpland, M., and Humboldt, on the pelagic shells found on the ridge of the Andes, 45.

Boussingault, on the depth at which is found the mean annual temperature within the tropics, 175; on the volcanoes of New Granada, 217; on the temperature of the earth in the tropics, 220, 221; temperature of the thermal springs of Las Trincheras, 222; his investigations on the chemical analysis of the atmosphere, 311, 312; on the mean annual quantity of rain in different parts of South America, 333, 334.

Bouvard, M., 105; his observations on that portion of the horary oscillations of the pressure of the atmosphere, which depends on the attraction of the moon 313.

Bramidos y truenos of Guanaxuato, 209, 210.

Brandes, falls of shooting stars, 114, 116; height and velocity of shooting stars, 120; their periodic falls, 125, 126.

Bravais, on the Aurora, 201; on the daily oscillations of the barometer in 70 degrees north latitude, 314; distribution of the quantity of rain in Central Europe, 334; doubts on the greater dryness of mountain air, 334.

Brewster, Sir David, first detected the connection between the curvature of magnetic lines and my isothermal lines, 193.

Brongniart, Adolphe, luxuriance of the primitive vegetable world, 218; fossil flora contained in coal measures, 280.

Brongniart, Alexander, formation of ribbon jasper, 259; one of the founders of the archaeology of organic life, 273.

Brown, Robert, first discoverer of molecular motion, 341.

Buch's, Leopold von, theory on the elevation of continents and mountain chains, 45; on the craters and circular form of the island of Palma, 226; on volcanoes, 234, 238, 242, 243, 247; on metamorphic rocks, 249-252, 260, 263, 264; on the origin of various conglomerates and rocks of detritus, 269; classification of ammonites, 276, 277; physical causes of the elevation of continents, 295; on the changes in height of the Swedish coasts, 295.

Buckland, 272; on the fossil flora of the coal measures, 279.

Buffon, his views on the geographical distribution of animals, 348.

Burckhardt, on the volcano of Medina, 246; on the hornitos de Jerullo, see note by Translator, 230.

Burnes, Sir Alexander, on the purity of the atmosphere in Bokhara, 114; propagation of shocks of earthquakes, 212.

p 365 Caile, La, pendulum measurements at the Cape of Good Hope, 169.

Caldas, quantity of rain at Santa Fe de Bogota, 334.

Camargo's MS. 'Historia de Tiascala', 140.

Capocci, his observations on periodic falls of aerolites, 126.

Carlini, geodesic experiments in Lombardy, 168; Mount Cenis, 170.

Carrara marble, 262, 263.

Carus, his definition of "Nature," 41.

Caspian Sea, its periodic rise and fall, 297.

Cassini, Dominicus, on the zodiacal light, 139, 140; hypothesis on 141; his discovery of the spheroidal form of Jupiter, 164.

Cautley, Capt, and Dr. Falconer, discovery of gigantic fossils in the Himalayas.

Cavanilles, first entertained the idea of seeing grass grow, 149.

Cavendish, use of the torsion balance to determine the mean density of the Earth, 170.

Challis, Professor, on the Aurora, March 19 and Oct. 24th, 1847, see note by Translator, 195, 199.

Chardin, noticed in Persia the famous comet of 1608, called "nyzek" or "petite lance," 139.

Charpentier, M., belemnites found in the primitive limestone of the Col de la Seigne, 261; glaciers, 329.

Chemistry as distinguished from physics, 62; chemical affinity, 63.

Chevandier, calculations on the carbon contained in the trees of the forests of our temperate zones, 281.

Childrey first described the zodical light in his Britannia Baconica, 138.

Chinese accounts of comets, 99, 100, 101; shooting stars, 128: "fire springs," 158; knowledge of the magnetic needle, 180; electro-magnetism, 188, 189.

Chladni on meteoric stones, etc., 118, 135; on the selenic origin of aerolites, 121; on the supposed phenomenon of ascending shooting stars, 122; on the obscuration of the Sun's disk, 133; sound-figures, 135; pulsations in the tails of comets, 143.

Choiseul, his chart of Lemnos, 246.

Chromatic polarization. See Polarization.

Cirro-cumulus cloud. See Clouds.

Cirrous Strata. See Clouds.

Clark, his experiments on the variations of atmospheric electricity, 335, 336.

Clarke, J. G., of Maine, U.S., on the comet of 1843, 100.

Climatic distribution of heat, 313, 317-328; of humidity, 328, 333, 334.

Climatology, 317-329; climate, general sense of, 317, 318.

Clouds, their electric tension, color, and height, 236, 337; connection of cirrous strata with the Aurora Borealis, 196; cirro-cumulus cloud, phenomena of, 197; luminous, 202; Dove on their formation and appearance, 315, 316; often present on a bright summer sky the "projected image" of the soil below, 316; volcanic, 233.

Coal formations, ancient vegetable remains in, 280, 281.

Coal mines, depth of, 158-160.

Colebrooke on the snow-line of the two sides of the Himalayas, 31.

Colladon, electro-magnetic apparatus, 335.

Columbus, his remark that "the Earth is small and narrow," 164; found the compass showed no variation in the Azores, 181, 182; of lava streams, 245; noticed conifers and palms growing together in Cuba, 282; remarks in his journal on the equatorial currents, 307; of the Sargasso Sea, 308; his dream, 310, 311.

Comets, general description of, 99-112; Biela's 43, 86, 107, 108; Blaupain's 108; Clausen's 108; Encke's, 43, 64, 86, 107-108; Faye's 107, 108; Halley's, 43, 100, 102-109; Lexell's and Burchardt's 108, 110; Messier's 108; Olbera's, 109; Pons's 109; famous one of 1608, seen in Persia, called "nyzek," or "petit lance," 189; comet of 1843, 101; their nucleus and tail, 87, 100; small mass, 100; diversity of form, 100-103; light, 104-106; velocity, 109; comets of short period, 107-109; long period, 109-110; number, 99; Chinese observations on, 99-101; value of a knowledge of their orbits, 43; possibility of collision of Blela's and Encke's comets, 107, 108; hypothesis of a resisting medium conjectured from the diminishing period of the revolution of Encke's comet, 106; apprehensions of their collision with the Earth, 108, 110, 111; their popular supposed influence on the vintage, 111.

Compass, early use of by the Chinese, 180; permanency in the West Indies, 181.

Condamine, La, inscription on a marble tablet at the Jesuit's College, Quito on the use of the pendulum as a measure of seconds, 166, 167.

Conde, notice of a heavy shower of shooting stars, Oct., 902, 119.

Coraboeuf and Delcrois, geodetic operations, 304.

Cordilleras, scenery of, 26, 29, 33; vegetation, 34, 35; intensity of the zodiacal light, 137.

Cosmography, physical, its object and ultimate aims, 57-60; materials, 60.

Cosmos, the author's object, 38, 78; primitive signification and precise definition of the word, 69; how employed by Greek and Roman writers, 69, 60; derivation, 70.

Craters. See Volcanoes.

Curtius, Professor, his notes on the temperature of various springs in Greece, 222, 223.

Cuvier, one of the founders of the archaeology of organic life, 273; discovery of fossil crocodiles in the tertiary formations, 274. Dainachos on the phenomena attending the fall of the stone of Aegos Potamos, 133, 134.

Dalman on the existence of Chionaea araneoides in polar snow, 344.

Dalton, observed the southern lights in England, 198.

Dante, quotation from, 322.

Darwin, Charles, fossil vegetation in the travertine of Van Diemen's Land, 224; central volcanoes regarded as volcanic chains of small extent on parallel fissures, 238; instructive materials in the temperate zones of the southern hemisphere for the study of the present and past geography of plants, 282, 283; on the fiord formation at the southeast end of America, 293; on the elevation and depression of the bottom of the South Sea, 297; rich luxuriance of animal life in the ocean, 309, 310; on the volcano of Aconcagua, 330.

Daubeney on volcanos. See Translator's notes, 161, 203, 204, 210, 218, 224, 228, 230, 233, 234, 235, 236, 244, 245.

Daussy, his barometric expriments, 208; observations on the velocity of the equatorial current, 307.

Davy, Sir Humphrey, hypothesis on active volcanic phenomena, 235; on the low temperature of water on shoals, 309.

Dead Sea, its depression below the level of the Mediterranean, 296, 297.

Dechen, Von, on the depth of the coal-basin of Liege, 160.

Delcrois. See Coraboeuf.

Descartes, his fragments of a contemplated work, entitled "Monde," 68; on comets, 139.

Deshayes and Lyell, their investigations on the numerical relations of extinct and existing organic life, 275.

Dicaearchus, his "parallel of the diaphragm," 289.

Diogenes Laertius, on the aerolite of Aegos Potamos, 116, 122, 134.

D'Orbigny, fossil remains from the Himalaya and the Indian plains of Cutch, 277.

Dove on the similar action of the declination needle to the atmospheric electrometer, 194; "law of rotation," 315; on the formation and appearance of clouds, 316; on the difference between the true temperature of the surface of the ground and the indications of a thermometer suspended in the shade, 325; hygrometric windrose, 333.

Doyere, his beautiful experiments on the tenacity of life in animalcules, 345.

Drake, shaking of the earth for successive days in the United States (1811-12), 211.

Dufrenoy et Elie de Beaumont, Geologie de la France, 253, 258, 259, 260, 262, 266.

Dumas, results of his chemical analysis of the atmosphere, 311.

Dunlop on the comet of 1825, 103.

Duperrey on the configuration of the magnetic equator, 183; pendulum oscillations, 166.

Duprez, influence of trees on the intensity of electricity in the atmosphere, 335.

Eandi, Vassalli, electric perturbation during the protracted earthquake of Pignorol, 206.

Earth, survey of its crust, 72; relative magnitude, etc., in the solar system, 95-97; general description of terrestrial phenomena, 154-360; geographical distribution, 161, 162; its mean density, 169-172; internal heat and temperature, 172-176; electro-magnetic activity, 177-193; conjectures on its early high temperature, 172; interior increase of heat with increasing depth, 161; greatest depths reached by human labor, 157-159; methods employed to investigate the curvature of its surface, 165-168; reaction of the interior on the external crust, 161, 202-247; general delineation of its reaction, 204-206; fantastic views on its interior, 171.

Earthquakes, general account of, 204-218; their manifestations, 204-206; of Riobamba, 204, 206, 208, 212, 214; Lisbon, 210, 211, 213, 214; Calabria, 206; their propagation, 204, 212, 213; waves of commotion, 205, 206, 212;

## action on gaseous and aqueous springs, 210, 222, 224; salses and mud

volcanoes, 224-228; erroneous popular belief on, 206-208; noise accompanying earthquakes, 208-210; their vast destruction of life, 210, 211; volcanic force, 214, 215; deep and peculiar impression produced on men and animals, 215, 216.

Ehrenberg, his discovery of infusoria in the polishing slate of Bilin, 150; infusorial deposits, 255, 262; brilliant discovery of microscopic life in the ocean and in the ice of the polar regions, 342; rapid propogation of animalcules and their tenacity of life, 343-345; transformation of chalk, 262.

Electricity, magnetic, 188-202; conjectured electric currents, 189, 190; electric storms, 194; atmospheric 335, 337.

Elevations, comparative, of mountains in the two hemispheres, 28, 29.

Encke, 106; his computation that the showers of meteors, in 1833, proceeded from the same point of space in the direction in which the earth was moving at the time, 119, 120.

Ennius, 71.

Epicharmus, writings of, 71.

Equator, advantages of the countries bordering on, 33, 34; their organic richness and fertility, 34, 35; magnetic equator, 183-185.

Erman, Adolph, on the three cold days of May (11th-13th), 133; lines of declination in Northern Asia, 182; in the southern parts of the Atlantic, 187; observations during the earthquake of Irkutsk, on the non-disturbance of the horary changes of the magnetic needle, 207.

Eruptions and exhalations (volcanic), lava, gaseous and liquid fluids, hot mud, mud mofettes, etc., 161, [other page numbers obscured in paper copy]

p 367 Ethnographical studies, their importance and teaching, 357, 358.

Euripides, his Phaeton, 122.

Falconer, Dr., fossil researches in the Himalayas, 278.

Faraday, radiating heat, electro-magnetism etc., 49, 179, 188; brilliant discovery of the evolution of light by magnetic forces, 193.

Farquharson on the connection of cirrous clouds with the Aurora, 197; its altitude, 199.

Federow, his pendulum experiments, 168.

Feldt on the ascent of shooting stars, 123.

Ferdinandes, igneous island of, 242.

Floras, geographical distribution of, 350.

Forbes, Professor E., reference to his Travels in Lycia, 223; account of the island of Santorino, 241, 242.

Forbes, Professor J., his improved selsmometer, 205; on the correspondence existing between the distribution of existing floras in the British Islands, 348, 349; on the origin and diffusion of the British flora, 353, 354.

Forster, George, remarked the climatic difference of temperature of the eastern and western coasts of both continents, 321.

Forster, Dr. Thomas, monkish notice of "Meteorodes," 123.

Fossil remains of tropical plants and animals found in northern regions, 46, 270-284; of extinct vegetation in the travertine of Van Diemen's Land, 224; fossil human remains, 250.

Foster, Reinhold, pyramidal configuration of the southern extremities of continents, 290, 291.

Fourier, temperature of our planetary system, 155, 172, 176.

Fracastoro on the direction of the tails of comets from the sun, 101.

Fraehn, fall of stars, 119.

Franklin, Benjamin, existence of sandbanks indicated by the coldness of the water over them, 308.

Franklin, Capt., on the Aurora, 197, 199, 200, 201; rarity of electric explosions in high northern regions, 337.

Freycinet, pendulum oscillations, 166.

Fusinieri on meteoric masses, 123.

Galileo, 104, 167.

Galle, Dr., 91.

Galvant, Aloysio, accidental discovery of galvanism, 52.

Gaseous emanations, fluids, mud, and molten earth, 217, 220.

Gasparin, distribution of the quantity of rain in Central Europe, 333.

Gauss, Friedrich, on terrestrial magnetism, 179; his erection. in 1832, of a magnetic observatory on a new principle, 191, 192.

Gay-Lussac, 204, 233, 234, 266, 267, 311, 312, 334, 336.

Geognostic or geological description of the earth's surface, 202-286.

Geognosy (the study of the textures and position of the earth's surface), its progress, 203.

Geography, physical, 288-311; of animal life, 341-346; of plants, 346-351.

Geographics, Ritter's (Carl), "Geography in relation to Nature and the History of Man," 48, 67; Varenius (Bernhard), General and Comparative Geography, 66, 67.

Gerard, Capts. A. G. and J. G., on the snow-line and vegetation of the Himalayas, 31, 32, 331, 332.

German scientific works, their defects, 47.

Geyser, intermittent fountains of, 222.

Gieseke on the Aurora, 200.

Gilbert, Sir Humphrey, Gulf Stream, 307.

Gilbert, William, of Colchester, terrestrial magnetism, 158, 159, 177, 179, 182.

Gillies, Dr., on the snow-line of South America, 330, 331.

Gioja, crater of, 98.

Girard, composition and texture of basalt, 253.

Glaisher, James, on the Aurora Borealis of Oct. 24, 1847. See Translator's notes, 194, 200.

Goldfuss, Professor, examination of fossil specimens of the flying saurians, 274.

Goppert on the conversion of a fragment of amber-tree into black coal, 281; eyeadeae, 283; on the amber-tree of the Baltic, 283, 284.

Gothe, 41, 47, 53.

Greek philosophers, their use of the term Cosmos, 69, 70; hypotheses on aerolites, 122, 123, 134.

Grimm, Jacob, graceful symbolism attached to falling stars in the Lithuanian mythology, 112, 113.

Gulf Stream, its origin and course, 307.

Gumprecht, pyroxenic nepheline, 253.

Guanaxuato, striking subterranean noise at, 209.

Hall, Sir James, his experiments on mineral fusion, 262.

Halley, comet, 43, 100, 102-109; on the meteor of 1686, 118, 133; on the light of stars, 152; hypothesis of the earth being a hollow sphere, 171; his bold conjecture that the Aurora Borealis was a magnetic phenomenon, 193.

Hansteen on magnetic lines of declination in Northern Asia, 182.

Hausen on the material contents of the moon, 96.

Hedenstrom on the so-called "Wood Hills" of New Siberia, 281.

Hegel, quotation from his "Philosophy of History," 76.

Heine, discovery of crystals of feldspar in scoriae, 268.

Hemmer, falling stars, 119.

Hencke, planets discovered by. See note by Translator, 90, 91.

Henfrey, A., extract from his Outlines of Structural and Physiological Botany. See notes by Translator, 341, 342, 351.

p 368 Hensius on the variations of form in the comet of 1744, 102.

Herodotus, described Scythia as free from earthquakes, 204; Scythian saga of the sacred gold, which fell burning from heaven, 115.

Herschel, Sir William, map of the world, 66; inscription on his monument at Upton, 87; satellites of Saturn, 96; diameters of comets, 101; on the comet of 1811, 103; star guagings, 150; starless space, 150, 152; time required for light to pass to the earth from the remotest luminous vapor, 154.

Herschel, Sir John, letter on Magellanic clouds, 85; satellites of Saturn, 98; diameter of nebulous stars, 141; stellar Milky Way, 150, 151; light of isolated starry clusters, 151; observed at the Cape, the star pi in Argo increase in splendor, 153; invariability of the magnetic declination in the West Indes, 181.

Hesiod, dimensions of the universe, 154.

Hevellus on the comet of 1618, 106.

Hibbert, Dr., on the Lake of Laach. See note by Translator, 218.

Himalayas, the, their altitude, 28; scenery and vegetation, 29, 30; temperature, 30, 31; variations of the snow-line on their northern and southern declivities, 30-33, 331.

Hind, Mr., planets discovered by. See Translator's note, 90, 91.

Hindoo civilization, its primitive seat, 35, 36.

Hippalos, or monsoons, 316.

Hippocrates, his erroneous supposition that the land of Scythia is an elevated table-land, 346.

Hoff, numerical inquiries on the distribution of earthquakes throughout the year, 207.

Hoffman, Friedrich, observations on earthquakes, 206-207; on eruption fissures in the Lipari Islands, 238.

Holberg, his Satire, "Travels of Nic. Klimius, in the world under ground." See Translator's note, 171, 172.

Hood on the Aurora, 200, 201.

Hooke, Robert, pulsations in the tails of comets, 143; his anticipation of the application of botannical and zoological evidence to determine the relative age of rocks, 270-272.

Ho-tsings, Chinese fire-springs, their depth, 158; chemical composition, 217.

Howard on the climate of London, 125; mean annual quantity of rain in London, 333.

Hugel, Carl von, on the elevation of the valley of Kashmir, 32, 33; on the snow-line of the Himalayas, 331.

Humboldt, Alexander von, works by referred to in various notes: Annales de Chimie et de Physique, 31, 305. Annales des Science Naturelles, 28. Ansichten der Natur, 342, 344, 347. Asie Centrale, 28, 31, 33, 115, 158, 159, 160, 204, 217, 219, 225, 245, 251, 252, 260, 289, 290, 291, 292, 296, 300, 301, 303-306, 320, 323, 324, 330, 331, 334, 350, 356. Atlas Geographique et Physique du Nouveau Continent, 33, 249. De distributione Geographica Plantrum, secundum coeli temperiem, et altitudinem Montium, 33, 291, 324. Examen Critique de l'Histoire de la Geographie, 58, 180, 181, 227, 289, 292, 307, 308, 310, 316, 356. Essai Geognostique sur le Gisement des Roches, 230, 252, 266, 300. Essai Politique sur la Nouvelle Espagne, 129, 240. Essai sur la Geographie des Plantes, 33, 230, 315. Flora Friburgensis Subterranea, 340, 346. Journal de Physique, 178, 292. Lettre au Duc de Sussex, sur les Moyens propres a perfectionner la connaissance du Magnetisme Terrestre, 178, 192. Monumens des Peuples Indigenes de l'Amerique, 140. Nouvelles Annales des Voyages, 307. Recueil d'Observations Astronomiques, 28, 167, 218, 327. Recueil d'Observations de Zoologi et d'Anatomie Comparee, 232. Relation Historique du Voyage aux Regions Equinoxiales, 113, 119, 123, 127, 130, 186, 206, 207, 220, 221, 225, 252, 292, 299, 300, 302, 305-307, 314, 315, 327, 329, 334, 336. Tableau Physique des Regions Equinoxiales, 33, 230. Vues des Cordilleres, 225, 230.

Humboldt, Wilhelm von, on the primitive seat of Hindoo civilization, 36; sonnet, extract from, 154; on the gradual recognition by the human race of the bond of humanity, 358, 359.

Humidity, 313, 332-335.

Hutton, Capt. Thomas, his paper on the snow-line of the Himalayas, 331, 332.

Huygens, polarization of light, 52; nebulous spots, 138.

Hygrometry, 332, 333; hygrometric wind-rose, 333.

Imagination, abuse of, by half-civilized nations, 37.

Imbert, his account of Chinese "fire-springs," 158.

Ionian school of natural philosophy, 65, 77, 84, 134.

Isogenic, isoclinical, isodynamic, etc. See Lines.

Jacquemont, Victor, his barometrical observations on the snow-line of the Himalayas, 32, 231.

Jasper, its formation, 259-261.

Jessen on the gradual rise of the coast of Sweden, 295.

Jorullo, hornitos de, 230.

p 369 Justinian, conjectures on the physical causes of volcanic eruptions, 243.

Kamtz, isobarometric lines, 315; doubts on the greater dryness of mountain air, 334.

Kant, Emmanuel, "on the theory and structure of the heavens," 50, 65; earthquake at Lisbon, 210.

Kelihau on the ancient sea-line of the coast of Spitzbergen, 296.

Kepler on the distances of stars, 88; on the density of the planets, 93; law of progression, 95; on the number of comets, 99; shooting stars, 113; on the obscuration of the sun's disk, 132; on the radiations of heat from the fixed stars, 136; on a solar atmosphere, 139.

Kloden, shooting stars, 119, 124.

Knowledge, superficial, evils of, 43.

Krug of Nidda, temperature of the Geyser and the Strokr intermittent fountains, 222.

Krusenstern, Admiral, on the train of a fire-ball, 114.

Kuopho, a Chinese physicist on the attraction of the magnet, and of amber, 168.

Kupffer, magnetic stations in Northern Asia, 191.

Lamanon, 187.

Lambert, suggestion that the direction of the wind be compared with the height of the barometer, alterations of temperature, humidity, etc., 315.

Lamont, mass of Uranus, 93; satellites of Saturn, 96.

Language and thought, their mutual alliance, 56; author's praise of his native language, 56.

Languages, importance of their study, 357, 359.

Laplace, his "Systeme du Monde," 48, 62, 92, 141; mass of the comet of 1770, 107; on the required velocity of masses projected from the Moon, 121, 122; on the altitude of the boundaries of the atmosphere of cosmical bodies, 141; zodiacal light, 141; lunar inequalities, 166; the Earth's form and size inferred from lunar inequalities, 168, 169; his estimate of the mean height of mountains, 301; density of the ocean required to be less than the earth's for the stability of its equilibrium, 305; results of his perfect theory of tides, 306.

Latin writers, their use of the term "Mundus," 70, 71.

Latitudes, Northern, obstacles they present to a discovery of the laws of Nature, 36; earliest acquaintance with the governing forces of the physical world, there displayed, 36; spread from thence of the germs of civilization, 36.

Latitudes, tropical, their advantages for the contemplation of nature, 33; powerful impressions, from their organic richness and fertility, 34; facilities they present for a knowledge of the laws of nature, 35; brilliant display of shooting stars, 113.

Laugier, his calculations to prove Halley's comet identical with the comet of 1378, described in Chinese tables, 109.

Lava, its mineral composition, 234.

Lavoisier, 62.

Lawrence (St.), fiery tears, 124; meteoric stream, 125.

Leibnitz, his conjecture that the planets increase in volume in proportion to their increase of distance from the Sun, 93.

Lenz, observations on the mean level of the Caspian Sea, 297; maxims of density of the oceanic temperature, 304; temperature and density of the ocean under different zones of latitude and longitude, 306.

Leonhard, Karl von, assumption on formations of granular limestone, 263.

Leverrier, planet Neptune. See Translator's note, 90, 91.

Lewy, observations on the varying quantity of oxygen in the atmosphere, according to local conditions, or the seasons, 311, 312.

Lichtenberg, on meteoric stones, 118.

Liebig on traces of ammonical vapors in the atmosphere, 311.

Light, chromatic polarization of, 52; transmission, 88; of comets, 104-106; of fixed stars, 105; extraordinary lightness, instances of, 142-144; propagation of 153; speed of transit, 153, 154. See Aurora, Zodiacal Light, etc.

Lignites or beds of brown coal, 283, 284.

Lines, isogonic (magnetic equal deviation), 177, 181-185; isoclinal (magnetis equal inclination), 178, 179, 181-185; isodynamic (or magnetic equal force), 181, 185-194; isogeothermal (chthonisothermal), 219; isobarometric, 315; isothermal, isotheral, and isochimenal, 317, 327, 328, 358.

Line of no variation of horary declination, 183; lower limit of perpetual snow, 329-332; phosphorescent, 113.

Lisbon, earthquake of, 210, 211, 213, 214.

Lord on the limits of the snow-line on the Himalayas, 32.

Lottin, his observations of the Aurora, with Bravais and Siljerstrom, on the coast of Lapland, 195, 200, 201.

Lowenorn, recognized the coruscation of the polar light in bright sunshine, 196.

Lyell, Charles, investigations on the numerical relations of extinct and organic life, 274, 275; nether-formed or hypogene rocks, 249; uniformity of the production of erupted rocks, 257. See notes by Translator, 203, 244, 257.

Mackenzie, description of a remarkable eruption in Iceland, 236.

Maclear on a Centauri, 88; parallaxes and distances of fixed stars, 153; increase in brightness of 'pi' Argo, 153.

Madler, planetary compression of Uranus, 96; distance of the innermost satellite of Saturn from the centre of that planet, 97; material contents of the Moon, 96; its libration, 98; mean depression of temperature on the three cold days of May (11th-13th), 133; conjecture that the average mass of the larger number of binary stars exceeds the mass of the Sun, 149.

Magellanic clouds, 85.

Magnetic attraction, 188; declination, 181-183; horary motion, 177-180; horary variations 183, 190; magnetic storms, 177, 179, 195, 199; their intimate connection with the Aurora, 193-201; represented by three systems of lines, see Lines; movement of oval systems, 182; magnetic equator, 183-185; magnetic poles, 183, 184; observatories, 190-192; magnetic stations, 190, 191, 317.

Magnetism, terrestrial, 177-193, 201; electro, 177-191.

Magnussen, Soemund, description of remarkable eruption in Iceland, 236.

Mahlmann, Wilhelm, south west direction of the aërial current in the middle latitudes of the temperate zone, 317.

Mairan on the zodiacal light, 138, 139, 142; his opinion that the Sun is a nebulous star, 141.

Malapert, annular mountain, 98.

Malle, Dureau de la, 223.

Man, general view of, 351-359; proofs of the flexibility of his nature, 27; results of his intellectual progress, 53, 54; geographical distribution of races, 351-356; on the assumption of superior and inferior races, 351-358; his gradual recognition of the bond of humanity, 358, 359.

Mantell, Dr., his "Wonders of Geology," see notes by Translator, 45, 64, 203, 274, 278, 281, 283, 284, 287; "Medals of Creation," 46, 271, 283, 287.

Margarita Philosophica by Gregory Reisch, 58.

Marius, Simon, first described the nebulous spots in Andromeda and Orion, 138.

Martins, observations on polar bands, 198; found that air collected at Faulhorn contained as much oxygen as the air of Paris, 312; on the distribution of the quantity of rain in Central Europe, 333; doubts on the greater dryness of mountain air, 334.

Matthessen, letter to Arago on the zodiacal light, 142.

Mathieu on the augmented intensity of the attraction of gravitation in volcanic islands, 167.

Mayer, Tobias, on the motion of the solar system, 146, 148.

Mean numerical values, their necessity in modern physical science, 81.

Melloni, his discoveries on radiating heat and electro-magnetism, 49.

Menzel, unedited work by, on the flora of Japan, 347.

Messier, comet, 108; nebulous spot resembling our starry stratum, 151.

Metamorphic Rocks. See Rocks.

Meteorology, 311-339.

Meteors, see Aërolites; meteoric infusoria, 345, 346.

Methone, Hill of, 240.

Meyen on forming a thermal scale of cultivation, 324; on the reproductive organs of liverworts and algae, 341.

Meyer, Hermann von, on the organization of flying saurians, 274.

Milky Way, its figure, 89; views of Aristotle on, 103; vast telescopic breadth, 150; Milky Way of nebulous spots at right angles with that of the stars, 151.

Minerals, artificially formed, 268, 269.

Mines, greatest depth of, 157, 159; temperature, 158.

Mist, phosphorescent, 142.

Mitchell, protracted earthquake shocks in North America, 211.

Mitscherlich on the chemical origin of iron glance in volcanic masses, 234; chemical combinations, a means of throwing a clear light on geognosy, 256; on gypsum, as a uniaxal crystal, 259; experiments on the simultaneously opposite actions of heat on crystalline bodies, 259; formation of crystals of mica, 260; on artificial mineral products, 268, 271.

Mofettes (exhalations of carbonic acid gas), 215-219.

Monsoons (Indian), 316, 317.

Monticelli on the current of hydrochloric acid from the crater of Vesuvius, 235; crystals of mica found in the lava of Vesuvius, 260.

Moon, the, its relative magnitude, 96; density, 96; distance from the earth, 97; its libration, 98, 163; its light compared with that of the Aurora, 201, 202; volcanic action in, 228.

Moons or satellites, their diameter, distances, rotation, etc., 95-99.

Morgan, John H. "on the Aurora Borealis of Oct. 24, 1847." See Translator's notes, 194, 199.

Morton, Samuel George, his magnificent work on the American Races, 362.

Moser's images, 202.

Mountains, in Asia, America, and Europe, their altitude, scenery, and vegetation, 27-30, 238, 347; their influence on climate, natural productions, and on the human race, its trade, civilization, and social condition, 291, 292, 299, 300, 327; zones of vegetation on the declivities of 29, 30, 327-329; snow-line of, 30-33, 330, 331.

Mud volcanoes. See Salses and Volcanoes.

Muller, Johannes, on the modifications of plants and aniimals within certain limitations, 353.

Muncke on the appearance of Auroras in certain districts, 198.

Murchison, Sir R., account of a large fissure through which melaphyre had been ejected, 258; classification of fossiliferous strata, 277; on the age of the Palaeosaurus and Thecodontosaurus of Bristol, 274.

Muschenbroek on the frequency of meteors in August, 125.

Myndius, Apollonius, on the Pythagorean doctrine of comets, 103, 104.

Nature, result of a rational inquiry into, 25; emotions excited by her contemplation, 25; striking scenes, 26; their sources of enjoyment, 26, 27; magnificence of the tropical scenery, 33, 34, 35, 344; religious impulses from a communion with nature, 37; obstacles to an active spirit of inquiry, 37; mischief of inaccurate observations, 38; higher enjoyments of her study, 38; narrow-minded views of nature, 38; lofty impressions produced on the minds of laborious observers, 40; nature defined, 41; her studies inexhaustible, 41; general observations, their great advantages, 42; how to be correctly comprehended, 72; her most vivid impressions earthly, 82.

Nature, philosophy of, 24, 37; physical description of, 66, 67, 73.

Nebulae, 84-86; nebulous Milky Way at right angles with that of the stars, 150-153; nebulous spots, conjectures on, 83-86; nebulous stars and planetary nebulae, 85, 151, 152; nebulous vapor, 83-86, 87, 152; their supposed condensation in conformity with the laws of attraction, 84.

Neilson, gradual depression of the southern part of Sweden, 295.

Nericat, Andrea de, popular belief in Syria on the fall of aerolites, 123.

Newton, discussed the question on the difference between the attraction of masses and molecular attraction, 63; Newtonian axiom confirmed by Bessel, 64; his edition of the Geography of Varenius, 66; Principia Mathematica, 67; considered the planets to be composed of the same matter with the Earth, 132; compression of the Earth, 165.

Nicholl, J. P., note from his account of the planet Neptune, 90, 91.

Nicholson, observations of lighting clouds, unaccompanied by thunder or indications of storm, 337.

Nobile, Antonio, experiments of the height of the barometer, and its influence on the level of the sea, 298.

Noggerath counted 792 annual rings in the trunk of a tree at Bonn, 283.

Nordmann on the existence of animalcules in the fluids of the eyes of fishes, 345.

Norman, Robert, invented the inclinatorium, 179.

Observations, scientific, mischief of inaccurate, 38; tendency of unconnected, 40.

Ocean, general view of, 292-311; its extent as compared with the dry land, 288, 289; its depth, 160, 302; tides, 304, 305; decreasing temperature at increased depths, 302; uniformity and constancy of temperature in the same spaces, 303; its currents and their various causes, 306-309; its phosphorescence in the torrid zone, 202; its action on climate, 303, 319-320; influence on the mental and social condition of the human race, 162, 291, 292, 294, 310; richness of its organic life, 300, 310; oceanic microscopic forms, 342, 343; sentiments excited by its contemplation, 310.

Oersted, electro-magnetic discoveries, 188, 191.

Olbers, comets, 104, 109; aerolites, 114, 118; on their planetary velocity, 121; on the supposed phenomena of ascending shooting stars, 123; their periodic return in August, 125; November stream, 126; prediction of a brilliant fall of shooting stars in Nov., 1867, 127; absence of fossil meteoric stones in secondary and tertiary formations, 131; zodiacal light, its vibration through the tails of comets, 143; on the transparency of celestial space, 152.

Olmsted, Denison of New Haven, Connecticut, observations of aerolites, 113, 118, 119, 124.

Oltmanns, Herr, observed continuously with Humboldt, at Berlin, the movements of the declination needle, 190, 191.

Ovid, his description of the volcanic Hill of Methone, 240.

Oviedo describes the weed of the Gulf Stream as Praderias de yerva (sea weed meadows), 308.

Palaeontology, 270-284.

Pallas, meteoric iron, 131.

Palmer, New Haven, Connecticut, on the prodigious swarm of shooting stars, Nov. 12 and 13, 1833, 124; on the non-appearance in certain years of the August and November fall of aerolites, 129.

Parallaxes of fixed stars, 88, 89; of the solar system, 145, 146.

Perry, Capt., on Auroras, their connection with magnetic perturbations, 197, 201; whether attended with any sound, 200; seen to continue throughout the day, 197; barometric observation at Port Bowen, 314, 315; rarity of electric explosions in northern regions, 337.

Patricius, St., his accurate conjectures on the hot springs of Carthage, 223, 224.

Peltier on the actual source of atmospheric electricity, 335, 336.

Pendulum, its scientific uses, 44; experiments with, 64, 166, 169, 170; employed to investigate the curvature of the earth's surface, 165; local attraction, its influence on the pendulum, and geognostic knowledge deduced from, 44, 45, 167, 168; experiments of Bessel, 64.

Pentland, his measurements of the Andes, 28.

Percy, Dr., on minerals artifically produced. See note by Translator, 268.

Permian system of Murchison, 277.

Perouse, La, expedition of, 186.

Persia, great comet seen in (1608), 139, 140.

Pertz on the large aerolite that fell in the bed of the River Narni, 116.

Peters, Dr., velocity of stones projected from Aetna, 122.

Peucati, Count Mazari, partial infection of calcareous beds by the contact of syenitic granite in the Tyrol, 262.

Phillips on the temperature of a coalmine at increasing depths, 174.

Philolaus, his astronomical studies, 65; his fragmentary writings, 68-71.

Philosophy of nature, first germ, 37.

Phosphorescence of the sea in the torrid zones, 202.

Physics, their limits, 50; influence of physical science on the wealth and prosperity of nations, 53; province of physical science, 59; distinction betweeen the physical 'history' and physical 'description' of the world, 71, 72; physical science, characteristics of its modern progress, 81.

Pindar, 227.

Plans, geodesic experiments in Lombardy, 168.

Planets, 89-99; present number discovered, 90. (See note by Translator on the most recent discoveries, 90, 91); Sir Isaac Newton on their composition, 132; limited physical knowledge of, 156, 157; Ceres, 64-92; Earth, 88-99; Juno, 64, 92-97, 106; Jupiter, 64, 87, 92-98, 202; Mars, 87, 91-94, 132; Mercury, 87, 92-94; Pallas, 64, 92; Saturn, 87, 92-94; Venus, 91-94, 202; Uranus, 90-94; planets which have the largest number of moons, 95, 96.

Plants, geographical distribution of, 346-350.

Plato on the heavenly bodies, etc., 69; interpretation of nature, 163; his geognostic views on hot springs, and volcanic igneous streams, 237, 238.

Pliny the elder, his Natural History, 73; on comets, 104; aerolites, 122, 123, 130; magnetism, 180; attraction of amber, 188; on earthquakes, 205, 207; on the flame of inflammable gas, in the district of Phasells, 223; rarity of jasper, 261; on the configuration of Africa, 292.

Pliny the younger, his description of the great eruption of Mount Vesuvius, and the phenomenon of volcanic ashes, 235.

Plutarch, truth of his conjecture that falling stars are celestial bodies, 133, 134.

Poisson on the planet Jupiter, 64; conjecture on the spontaneous ignition of meteoric stones, 118; zodiacal light, 141; theory on the earth's temperature, 172, 173, 174, 176, 177.

Polarization, chromatic, results of its discovery, 52; experiments on the light of comets, 105, 106.

Polybius, 291.

Posidonius on the Ligyran field of stones, 115, 116.

Pouilet on the actual source of atmospheric electricity, 335.

Prejudices against science, how originated, 38; against the study of the exact sciences, why fallacious, 40-52.

Prichard, his physical history of Mankind, 352.

Pseudo-Plato, 54.

Psychrometer, 332, 338.

Pythagoras, first employed the word Cosmos in its modern sense, 69.

Pythagoreans, their study of the heavenly bodies, 65; doctrine on comets, 103.

Quarterly Review, article on Terrestrial Magnetism, 192.

Quetelet on aerolites, 114; their periodic return in August, 125.

Races, human, their geographical distribution, and unity, 351, 359.

Rain drops, temperature of, 220; mean annual quantity in the two hemispheres, 333, 334.

Reich, mean density of the earth, as ascertained by the torsion balance, 170; temperature of the mines in Saxony, 174.

Reisch, Gregory, his "Margarita Philosophica," 58.

Remusat, Abel, Mongolian tradition on the fall of an aerolite, 116; active volcanoes in Central Asia, at great distances from the sea, 245.

Richardson, magnetic phenomena attending the Aurora, 197; whether accompanied by sound 200; influence on the magnetic needle of the Aurora, 201.

Riohamba, earthquake at, 204, 205, 208, 213, 214.

Ritter, Carl, on his "Geography in relation to Nature and the History of Man," 48, 67.

Robert, Eugene, on the ancient sea-line on the coast of Spitzbergen, 296.

Robertson on the permanency of the compass in Jamaica, 181.

Rocks, their nature and configuration, 228; geognostical classification into four groups, 248-251; i. rocks of eruption, 248, 251-253; ii. sedimentary rocks, 248, 254, 255; iii. transformed, or metamorphic rocks, 248, 259, 255, 256-269; iv. conglomerates, or rocks of detritus, 269, 270; their changes from the action of heat, 258, 259; phenomena of contact, 258-269; effects of pressure and the rapidity of cooling, 258, 267.

Rose, Gustav, on the chemical elements, etc., of various aerolites, 131; on the structural relations of volcanic rocks, 254; on crystals of feldspar and albite found in granite, 251; relations of position in which granite occurs, 252-269; chemical process in the formation of various minerals, 265-269.

Ross, Sir James, his soundings with 27,000 feet of line, 160; magnetic observations at the South Pole, 187; important results of the Antarctic magnetic expedition in 1839, 192; rarity of electric explosions in high northern regions, 337.

Rossell, M. de, his magnetic oscillation experiments, and their date of publication, 186, 187.

Rothmann, confounded the setting zodiscal light with the cessation of twilight, 143.

Rozier, observation of a steady luminous appearance in the clouds, 202.

Rumker, Encke's comet, 106.

Ruppell denies the existence of active volcanoes in Kordofan, 245.

Sabine, Edward, observations on days of unusual magnetic disturbances, 178; recent magnetic observations, 184, 185, 187, 188.

Sagra, Ramon de la, observations on the mean annual quantity of rain in the Havana, 333.

Saint Pierre, Bernardin de, Paul and Virginia, 26; Studies of Nature, 347.

Salses or mud volcanoes, 224-228; striking phenomena attending their origin, 224, 225.

Salt works, depth of 158, 159; temperature, 174.

Santorino, the most important of the islands of eruption, 241, 242; description of. See note by Translator, 241.

Sargasso Sea, its situation, 308.

Satellites revolving round the primary planets, their diameter, distance, rotation, etc., 94, 99; Saturn's 96-98, 127' Earth's see Moon, Jupiter's, 96, 97; Uranus, 96-98.

Saurians, flying, fossil remains of, 274, 275.

Saussure, measurements of the marginal ledge of the crater of Mount Vesuvius, 232; traces of ammoniacal vapors in the atmosphere, 311; hygrometric measurements with Humboldt, 334-336.

Schayer, microscopic organisms in the ocean, 342, 343.

Scheerer on the identity of eleolite and nepheline, 253.

Schelling on nature, 55; quotation from his Giordino Bruino, 77.

Scheuchzner's fossil salamander, conjectured to be an antediluvian man, 274.

Schiller, quotation from, 36.

Schnurrer on the obscuration of the sun's disk, 133.

Schouten, Cornelius, in 1616 found the declination null in the Pacific, 182.

Schouw, distribution of the quantity of rain in Central Europe, 333.

Schrieber on the fragmentary character of meteoric stones, 117.

Scientific researches, their frequent result, 50; scientific knowledge a requirement of the present age, 53, 54; scientific terms, their vagueness and misapplication, 58, 68.

Scina, Abbate, earthquakes unconnected with the state of the weather, 206, 207.

Scoresby, rarity of electric explosions in high northern regions, 337.

Sea. See Ocean.

Seismometer, the, 205.

Seleucus of Erythrea, his astronomical studies, 65.

Seneca, noticed the direction of the tails of comets, 102; his views on the nature and paths of comets, 103, 104; omens drawn from their sudden appearance, 111; the germs of later observations on earthquakes found in his writings, 207; problematical extinction and sinking of Mount Aetna, 227, 240.

Shoals, atmospheric indications of their vicinity, 309.

Sidereal systems, 89, 90.

Siljerstrom, his observations on the Aurora, with Lottin and Bravais, on the coast of Lapland, 195.

Sirowatskoi, "Wood Hills" in New Siberia, 281.

Snow-line of the Himalayas, 30-33, 331, 334; of the Andes, 330; redness of long-fallen snow, 344.

Solar system, general description, 90-154; its position in space, 89; its transistory motion, 145-150.

Solinus on mud volcanoes, 225.

Sommering on the fossil remains of the large vertebrata, 274.

Somerville, Mrs., on the volume of fire-balls and shooting stars, 116; faintness of light of planetary nebulae, 141.

Southern celestial hemisphere, its picturesque beauty, 85, 86.

Spontaneous generation, 345, 346.

Springs, hot and cold, 219-225; intermittent, 219; causes of their temperature, 220-222; thermal, 222, 345; deepest Artesian wells the warmest, observed by Arago, 223; salses, 224-226; influence of earthquake shocks on hot springs, 210, 222-224.

Stars, general account of, 85-90; fixed 89, 90, 104; double and multiple, 89, 147; nebulous, 85, 86, 151, 152; their translatory motion, 147-150; parallaxes and distances, 147-149; computations of Bessel and Herschel on their diameter and volume, 148; immense number in the Milky Way, 150, 151; star dust, 85; star gaugings, 150; starless spaces, 150, 152; telescopic stars, 152; velocity of the propagation of light of, 153, 154; apparition of new stars, 153.

Storms, magnetic and volcanic. See Magnetism, Volcanoes.

Strabo, observed the cessation of shocks of erthquake on the eruption of lava, 215; on the mode in which islands are formed, 227; description of the Hill of Methone, 240; volcanic theory, 243; divined the existence of a continent in the northern hemisphere between Theria and Thine, 289; extolled the varied form of our small continent as favorable to the moral and intellectual development of its people, 291, 292.

Struve, Otho, on the proper motion of the solar system, 146; investigations on the propagation of light, 153; parallaxes and distances of fixed stars, 153; observations on Halley's comet, 105.

Studer, Professor, on mineral metamorphism. See note by Translator, 248.

Sun, magnitude of its volume compared with that of the fixed stars, 136; obscuration of its disk, 132; rotation round the center of gravity of the whole solar system, 145; velocity of its translatory motion, 145; narrow limitations of its atmosphere as compared with the nucleus of other nebulous stars, 141; "sun stones" of the ancients, 122; views of the Greek philosophers on the sun, 122.

Symond, Lieut., his trigonometrical survey of the Dead Sea, 296, 297.

Tacitus, distinguished local climatic relations from those of race, 352.

Temperature of the globe, see Earth and Ocean; remarkable uniformity over the same spaces of the surface of the ocean, 303; zones at which occur the maxima of the oceanic temperature, 319; causes which lower the temperature, 319, 320; temperature of various places, annual, and in the different seasons, 322, 323-328; thermic scale of temperature, 324, 325; of continental climates as compared with insular and littoral climates, 321, 322; law of decrease with increase of elevation, 327; depression of, by shoals, 309; refrigeration of the lower strata of the ocean, 303.

Teneriffe, Peak of its striking scenery, 26.

Theodectes of Phaselis on the color of the Ethiopians, 353.

Theon of Alexandria described comets as "wandering light clouds," 100.

Theophylactus described Scythia as free from earthquakes, 204.

Thermal scales of cultivated plants, 324, 325.

Thermal springs, their temperature, constancy, and change, 221-224; animal and vegetable life in, 345.

Thermometer, 338.

Thibet, habitability of its elevated plateaux, 331, 332.

Thienemann on the Aurora, 197, 200.

Thought, results of its free action, 53, 54; union with language, 56.

Tiberias, Sea of, its depression below the level of the Mediterranean, 296.

Tides of the ocean, their phenomena, 305, 306.

Tillard, Capt., on the sudden appearance of the island of Sabrina, 242.

Tournefort, zones of vegetation on Mount Ararat, 347.

Tralles, his notice of the negative electricity of the air near high waterfalls, 336.

Translator, notes by, 29; on the increase of the earth's internal heat with increase of depth, 45; silicious infusoria and animalculites, 46; chemical analysis of an aerolite, 64; on the recent discoveries of planets, 90, 91; observed the comet of 1843, at New Bedford, Massachusetts, in bright sunshine, 101; on meteoric stones, 111; on a MS., said to be in the library of Christ's College, Cambridge, 124; on the term "salses," 161; on Holberg's satire, "Travels in the World under Ground," 171; on the Aurora Borealis of Oct. 24, 1847, 194, 195, 199; on the electricity of the atmosphere during the Aurora, 200; on volcanic phenomena, 203, 204; description of the seismometer, 205; on the great earthquake of Lisbon, 210; impression made on the natives and foreigners by earthquakes in Peru, 215; earthquakes at Lima, 216, 217; on the gaseous compounds of sulphur, 217, 218; on the Lake of Lasch, its craters, 218; on the emissions of inflammable gas in the district of Phasells, 233; on true volcanoes as distinguished from salses, 224; on the volcano of Pichincha, 228; on the hornitos de Jorullo, as seen by Humboldt, 230; general rule on the dimensions of craters, 230; on the ejection of fish from the volcano of Imbaburn, 223; on the little isle of Volcano, 234; volcanic steam of Pantellaria, 235; on Daubeney's work "On Volcanoes," 236; account of the island of Santorino, 241; on the vicinity of extinct volcanoes to the sea, 244; meaning of the Chinese term "li," 245; on mineral metamorphism, 248; on fossil human remains found in Guadaloupe, 250; on minerals artifically produced 267, 268; fossil organic structures, 271, 272; on Coprolites, 271; geognostic distribution of fossils, 276; fossil fauna of the Sewalik Hills, 278; thickness of coal measures, 281; on the amber pine forests of the Baltic, 283, 284; elevation of mountain chains, 286, 287; the dinornis of Owen, 287; depth of the atmosphere, 302; richness of organic life in the ocean, 309; on filaments of plants resembling the spermatozoa of animals, 341; on the Diatomaceae in the South Arctic Ocean, 343; on the distribution of the floras and faunas of the British Isles, 348, 349; on the origin and diffusion of the British flora, 353, 354.

Translatory motion of the solar system, 145-150.

Trogus, Pompeius, on the supposed necessity that volcanoes were dependent on their vicinity to the sea for their continuance, 243, 244; views of the ancients on spontaneous generation, 346.

Tropical latitudes, their advantages for the contemplation of nature, 33; powerful impressions from their organic richness and fertility, 34; facilities they present for a knowledge of the laws of nature 35; transparency of the atmosphere, 114; phosphorescence of the sea, 202.

Tschudi, Dr., extract from his "Travels in Peru." See Translator's note, 215, 216, 217.

Turner, note on Sir Isaac Newton, 132.

Universality of animated life, 342, 343.

Valz on the comet of 1618, 106.

Varenius, Bernhard, his excellent general and comparative Geography, 66, 67; edited by Newton, 66.

Vegetable world, as viewed with microscopic powers of vision, 341; its predominance over animal life, 343.

Vegetation, its varied distribution on the earth's surface, 29-31, 62; richness and fertility in the tropics, 33-35; zones of vegetation on the declivities of mountains, 29-32, 346-350. See Aetna, Cordilleras, Himalayas, Mountains.

Vico, satellites of Saturn, 96.

Vigne, measurement of Ladak, 322.

Vine, thermal scale of its cultivation, 324.

Volcanoes, 28, 30, 35, 159, 161, 214, 215, 224-248; author's application of the term volcanic, 45; active volcanoes, safety-valves for their immediate neighborhood, 214; volcanic eruptions, 161, 210-270; mud volcanoes or salses, 224-228; traces of volcanic action on the surface of the earth and moon, 228; influence of relations of height on the occurrence of eruptions, 228-233; volcanic storm, 233; volcanic ashes, 233; classification of volcanoes into central and linear, 238; theory of the necessity of their proximity to the sea, 243-246; geographical distribution of still active volcanoes, 245-247; metamorphic action on rocks, 247-249.

Vrolik, his anatomical investigations on the form of the pelvis, 352, 353.

Wagner, Rudolph, notes on the races of Africa, 352.

Walter on the decrease of volcanic activity, 215.

Wartmann, meteors, 113, 114.

Weber, his anatomical investigations on the form of the pelvis, 353.

Webster, Dr. (of Harvard College, U.S.), account of the island named Sabrina. See note by Translator, 242.

Winds, 315-321; monsoons, 316, 317; trade winds, 32-, 321; law of rotation, importance of its knowledge, 315-317.

Wine on the temperature required for its cultivation, 324; thermic table of mean annual heat, 325.

Wolleston on the limitation of the atmosphere, 302.

Wrangel, Admiral, on the brilliancy of the Aurora Borealis, coincident with the fall of shooting stars, 126, 127; observations of the Aurora, 197, 200; wood hills of the Siberian Polar Sea, 281.

Xenophanes of Colophon, described comets as wandering light clouds, 100; marine fossils found in marble quarries, 263.

Young, Thomas, earliest observer of the influence different kinds of rocks exercise on the vibrations of the pendulum, 168.

Yul-sung, described by Chinese writers as "the realm of pleasure," 332.

Zimmerman, Carl, hypsometrical remarks on the elevation of the Himalayas, 32.

Zodiacal light, conjectures on, 86-92; general account of, 137-144; beautiful appearance, 137, 138; first described in Childrey's Britannia Baconica, 138; probable causes, 141; intensity in tropical climates, 142.

Zones, of vegetation, on the declivities of mountains, 29-33; of latitude, their diversified vegetation, 62; of the southern heavens, their magnificence, 85, 86; polar, 197, 198.

END OF VOL. I.