part 1

(1875).

[2096] _Tractado_, etc., Burgos, 1578. c. 48.—After speaking of the virtues of the seeds, he adds—“tambien las buenas mugeres de aquellas partes, amigas de sus maridos, les dă hasta quatro destos por la boca, para embiar a los pobretos al otro mundo”!

[2097] _Hortus Malabaricus_, ii. tab. 33.

[2098] _Herbarium Amboinense_, iv. tab. 42.

[2099] Ainslie, Mat. _Med. of Hindoostan_, 1813. 292.

[2100] The oil was very expensive. I find by the books of Messrs. Allen and Hanburys, that the seeds cost in 1824, 10s., and in 1827, 18s. per lb. The oil was purchased in 1826 by the same house at 8_s._ to 10_s._ per ounce.—D. H.

=Description=—Croton seeds are about half an inch long, by nearly ⅖ of an inch broad, ovoid or bluntly oblong, divided longitudinally into two unequal parts, of which the more arched constitutes the dorsal and the flatter the ventral side. From the hilum, a fine raised line (raphe) passes to the other end of the seed, terminating in a darker point, indicating the chalaza. The surface of the seed is more or less covered with a bright cinnamon-brown coat, which when scraped shows the thin, brittle, black testa filled with a whitish, oily kernel, invested with a delicate seed-coat. The kernel is easily split into two halves consisting of oily albumen, between which lie the large, veined, leafy cotyledons and the radicle. The taste of the seed is at first merely oleaginous, but soon becomes unpleasantly and persistently acrid.

=Microscopic Structure=—The testa consists of an outer layer of radially arranged, much elongated and thick-walled cells; the inner parenchymatous layer contains small vascular bundles. The soft tissue of the albumen is loaded with drops of fatty oil. If this is removed by means of ether and weak potash lye, there remain small granules of albuminoid matter, the so-called _Aleuron_, and crystals of oxalate of calcium.

=Chemical Composition=—The principal constituent of croton seeds is the fatty oil, the _Oleum Crotonis_ or _Oleum Tiglii_ of pharmacy of which the kernels afford from 50 to 60 per cent. That used in England is for the most part expressed in London, and justly regarded as more reliable than that imported from India, with which the market was formerly supplied. It is a transparent, sherry-coloured, viscid liquid, slightly fluorescent, and having a slight rancid smell and an oily, acrid taste. Its solubility in alcohol (·794) appears to depend in great measure on the age of the oil, and the greater or less freshness of the seeds from which it was expressed,—oxidized or resinified oil dissolving the most readily.[2101] We found the oil which one of us had extracted by means of bisulphide of carbon to be levogyre.

Croton oil consists chiefly of the glycerinic ethers of the common fatty acids, such as stearic, palmitic, myristic and lauric acids. They

## partly separate in the cold; the acids also may partly be obtained by

passing nitrous acid through croton oil. There are also present in the latter, in the form of glycerinic ethers, the more volatile acids, as formic, acetic, isobutyric and one of the valerianic acids.[2102] The volatile part of the acids yielded by croton oil contains moreover an acid which was regarded by Schlippe (1858) as angelic acid, C₅H₈O₂. Yet in 1869 it was shown by Geuther and Frölich to be a peculiar acid, which they called _Tiglinic acid_. Its composition answers to the same formula, C₄H₇COOH, as that of angelic acid; but the melting points (angelic acid 45°, tiglinic 64° C.) and boiling points (angelic acid 185°, tiglinic 198°·5) are different. Both these acids have been mentioned in our article on Flores Anthemidis, at page 386. Tiglinic acid may also be obtained artificially; it is the methylcrotonic acid of Frankland and Duppa (1865).

Schlippe also stated croton oil to afford a peculiar liquid acid termed _Crotonic Acid_, C₄H₆O₂. According to Geuther and Frölich, however, an acid of this formula does not occur at all in croton oil. By synthetic methods three different acids of that composition are obtainable.

The _drastic principle_ of croton oil has not yet been isolated. Buchheim[2103] suggested that the action of the oil depends upon “_Crotonoleic acid_,” which however he failed in isolating satisfactorily. It is remarkable that the wood and leaves of _Croton Tiglium_ appear to partake also of the drastic properties of the seeds.

Schlippe asserts that he has separated the _vesicating matter_ of croton oil: if the oil be agitated with alcoholic soda, and afterwards with water, the supernatant liquor will be found free from acridity, while the alcoholic solution will yield, on addition of hydrochloric acid, a small quantity of a dark brown oil, called _Crotonol_, possessing vesicating properties. We have not succeeded in obtaining it, nor, so far as we know, has any other chemist except its discoverer.

The shells of the seeds (testa) yield upon incineration 2·6 per cent. of ash; the kernels dried at 100° C. 3·0 per cent.

=Commerce=—The shipments of croton seeds arrive chiefly from Cochin or Bombay, packed in cases, bales or robbins; but there are no statistics to show the extent of the trade.

[2101] Warrington, _Pharm. Journ._ vi. (1865) 382-387.

[2102] Schmidt and Berendes, 1878.

[2103] In the _Jahresbericht_ of Wiggers and Husemann, 1873. 560.

=Uses=—Croton seeds are not administered. The oil is given internally as a powerful cathartic, and is applied externally as a rubefacient.

=Substitutes=—The seeds of _Croton Pavanæ_ Hamilton, a native of Ava and Camrup (Assam), and those of _C. oblongifolius_ Roxb., a small tree common about Calcutta, are said to resemble those of _C. Tiglium_ L., but we have not compared them. Those of _Baliospermum montanum_ Müll. Arg. (_Croton polyandrus_ Roxb.) partake of the nature of croton seeds, and according to Roxburgh are used by the natives of India as a purgative.

SEMEN RICINI.

_Semen Cataputiæ majoris_; _Castor Oil Seeds_, _Palma Christi Seeds_; F. _Semence de Ricin_; G. _Ricinussamen_.

=Botanical Origin=—_Ricinus communis_ L., the castor oil plant, is a native of India where it bears several ancient Sanskrit names.[2104] By cultivation, it has been distributed through all the tropical and many of the temperate countries of the globe. In the regions most favourable to its growth, it attains a height of 40 feet. In the Azores, and the warmer Mediterranean countries as Algeria, Egypt, Greece, and the Riviera, it becomes a small tree, 10 to 15 feet high; while in France, Germany, and the south of England, it is an annual herb of noble foliage, growing to a height of 4 or 5 feet. In good summers, it ripens seeds in England and even as far north as Christiania in Norway.

_Ricinus communis_ exhibits a large number of varieties, several of which have been described and figured as distinct species. Müller, after a careful examination of the whole series, maintains them as a single species, of which he allows 16 forms, more or less well marked.[2105]

=History=—The castor oil plant was known to Herodotus who calls it Κίκι, and states that it furnishes an oil much used by the Egyptians, in whose ancient tombs seeds of Ricinus are, in fact, met with.[2106] At the period when Herodotus wrote, it would appear to have been already introduced into Greece, where it is cultivated to the present day under the same ancient name.[2107] The _Kikajon_ of the Book of Jonah, rendered by the translators of the English Bible _gourd_, is believed to be the same plant. Κίκι is also mentioned by Strabo as a production of Egypt, the oil from which is used for burning in lamps and for unguents.

[2104] The most ancient and most usual is _Eranda_; this word has passed into several other Indian languages.

[2105] De Candolle, _Prodr._, xv. sect. 2. 1017.

[2106] _Journ. of Botany_, 1879, 54.

[2107] Heldreich, _Nutzpflanzen Griechenlands_, Athen, 1862. 58.

Theophrastus and Nicander give the castor oil plant the name of Κρότων. Dioscorides, who calls it Κίκι or Κρότων, describes it as of the stature of a small fig-tree, with leaves like a plane, and seeds in a prickly pericarp, observing that the name Κρότων is applied to the seed on account of its resemblance to an insect [_Ixodes Ricinus_ Latr.], known by that appellation. He also gives an account of the process for extracting castor oil (Κίκινον ἔλαιον), which he says is not fit for food, but is used externally in medicine; he represents the seeds as extremely purgative. There is a tolerably correct figure of _Ricinus_ in the famous MS. Dioscorides which was executed for the Empress Juliana Anicia in A.D. 505, and is now preserved in the Imperial Library at Vienna.

The castor oil plant was cultivated by Albertus Magnus, Bishop of Ratisbon, in the middle of the 13th century.[2108] It was well known as a garden plant in the time of Turner (1568), who mentions the oil as _Oleum cicinum vel ricininum_.[2109] Gerarde, at the end of the same century, was familiar with it under the name of _Ricinus_ or _Kik_. The oil he says is called _Oleum cicinum_ or _Oleum de Cherua_,[2110] and used externally in skin diseases.

After this period the oil seems to have fallen into complete neglect, and is not even noticed in the comprehensive and accurate _Pharmacologia_ of Dale (1693). In the time of Hill (1751) and Lewis (1761) Palma Christi seeds were rarely found in the shops, and the oil from them was scarcely known.[2111]

In 1764 Peter Canvane, a physician who had practised many years in the West Indies, published a “_Dissertation on the Oleum Palmæ Christi, sive Oleum Ricini; or (as it is commonly call’d) Castor Oil_,”[2112] strongly recommending its use as a gentle purgative. This essay, which passed through two editions, and was translated into French, was followed by several others,[2113] thus thoroughly drawing attention to the value of the oil. Accordingly we find that the seeds of _Ricinus_ were admitted to the London Pharmacopœia of 1788, and directions given for preparing oil from them. Woodville in his _Medical Botany_ (1790) speaks of the oil as having “_lately come into frequent use_.”

At this period and for several years subsequently, the small supplies of the seeds and oil required for European medicine were obtained from Jamaica.[2114] This oil was gradually displaced in the market by that produced in the East Indies: the rapidity with which the consumption increased may be inferred from the following figures, representing the value of the Castor Oil shipped to Great Britain from Bengal in three several years, namely 1813-14, £610; 1815-16, £1269; 1819-20, £7102.[2115]

[2108] _De Vegetabilibus_, ed. Jessen, 1867. 347.

[2109] Turner’s _Herbal_, pt. ii. 116.

[2110] From the Arabic _khirva_, _i.e._ Palma Christi.

[2111] Hill, _Hist. of the Mat. Med._, Lond. 1751. 537.—Lewis, _Hist. of the Mat. Med._, Lond. 1761. 468.

[2112] The word _castor_ in connection with the seeds and oil of _Ricinus_ has come to us from Jamaica, in which island, by some strange mistake, the plant was once called _Agnus Castus_. The true Agnus Castus (_Vitex Agnus castus_ L.) is a native of the Mediterranean countries and not of the West Indies.

[2113] For a list of which consult Mérat et De Lens, _Dict. de Mat. Méd._ vi. (1834) 95.

[2114] How small was the traffic in Castor Oil in those days, may be judged from the fact that the stock in 1777 of a London wholesale druggist (Joseph Gurney Bevan, predecessor of Allen and Hanburys) was 2 Bottles (1 Bottle = 18 to 20 ounces) valued at 8_s._ per bottle. The accounts of the same house show at stocktaking in 1782, 23 Bottles of the oil, which had cost 10_s._ per bottle. In 1799 Jamaica exported 236 Casks of Castor Oil and 10 Casks of seeds (Renny, _Hist. of Jamaica_, 1807. 235).

[2115] H. H. Wilson, _Review of the External Commerce of Bengal from 1813 to 1828_, Calcutta, 1830, tables pp. 14-15.

=Description=—The fruit of _Ricinus_ is a tricoccous capsule, usually provided with weak prickles, containing one seed in each of its three cells. The seeds attain a length of ³/₁₀ to ⁶/₁₀, and a maximum breadth of ⁴/₁₀ of an inch, and are of a compressed ellipsoid form. The apex of the seed is prolonged into a short beak, on the inner side of which is a large tumid caruncle: from this latter proceeds the raphe as far as the lower end of the ventral surface, where it forks, its point of disappearance through the testa being marked by a minute protuberance. If the caruncle is broken off, a black scar, formed of two little depressions, remains.

The shining grey epidermis is beautifully marked with brownish bands and spots, and in this respect exhibits a great variety of colours and markings. It cannot be rubbed off, but may after maceration be peeled off in leathery strips. The black testa, grey within, is not thicker than in croton seed, but is much more brittle. The kernel or nucleus fills the testa completely, and is easily separated, still covered by the soft white inner membrane.

The kernel in respect to structure and situation of the embryo, agrees exactly with that of _Croton Tiglium_ (p. 565), excepting that the somewhat gaping cotyledons of _Ricinus_ are proportionately broader, and have their thick midrib provided with 2 or 3 pairs of lateral veins. If not rancid, the kernel has a bland taste, with but very slight acridity.

=Microscopic Structure=—The thin epidermis consists of pentagonal or hexagonal porous tabular cells, the walls of which are penetrated in certain spots by brownish colouring matter, whence the singular markings on the seed. It is these cells only that become blackened when a thin tangential slice is saturated with a solution of ferric chloride in alcohol.

Beneath these tabular cells there is found in the unripe seed[2116] a row of encrusted colourless cells, deposited in a radial direction on the testa. In the mature seed this layer of cells is not perceptible, and therefore appears to perish as the seed ripens. The testa itself is built up of cylindrical, densely packed cells, 300 to 320 mkm. long, and 6 to 10 mkm. in diameter. The kernel shares the structure of that of _C. Tiglium_, but is devoid of crystals of oxalate of calcium. If the endopleura of _Ricinus_ is moistened with dilute sulphuric acid, acicular crystals of sulphate of calcium separate from it after a few hours.

When thin slices of the kernel are examined under concentrated glycerin, no drops of oil are visible, notwithstanding the abundance of this latter; and it becomes conspicuous only by addition of much water. Hence it is probable that the oil exists in the seed as a kind of compound with its albuminoid contents.[2117] As to the latter, they partly form in the albumen of _Ricinus_ beautiful octohedra or tetrahedra, which are also found in many other seeds.[2118]

[2116] Gris, _Annales des Sciences Nat._, Bot., xv. (1861) 5-9.

[2117] Sachs, _Lehrbuch der Botanik_, 1874. 54.

[2118] For further particulars, see Trécul, _Ann. des Sc. Nat._, Bot., x.,(1858) 355; Radlkofer, _Krystalle proteinartiger Körper_, Leipzig, 1859. 61. and tab. 2 fig. 10; Pfeffer, _Proteïnkörner_ in Pringsheim’s _Jahrbücher für wissenschaftliche Botanik_, viii. (1872) 429. 464.

=Chemical Composition=—The most important constituent of the seed is the fixed oil, called _Castor Oil_, of which the peeled kernels afford at most half of their weight.

The oil, if most carefully prepared from peeled and winnowed seeds by pressure without heat, has but a slightly acrid taste, and contains only a very small proportion of the still unknown drastic constituent of the seeds. Hence the seeds themselves, or an emulsion prepared with them, act much more strongly than a corresponding quantity of oil. Castor oil, extracted by absolute alcohol or by bisulphide of carbon, likewise purges much more vehemently than the pressed oil.

The castor oil of commerce has a sp. gr. of about 0·96, usually a pale yellow tint, a viscid consistence, and a very slight yet rather mawkish odour and taste. Exposed to cold, it does not in general entirely solidify until the temperature reaches -18° C. In thin layers it dries up to varnish-like film.

Castor oil is distinguished by its power of mixing in all proportions with glacial acetic acid or absolute alcohol. It is even soluble in four parts of spirit of wine (·838) at 15° C., and mixes without turbidity with an equal weight of the same solvent at 25° C. The commercial varieties of the oil however differ considerably in these as well as in some other respects.

The optical properties of the oil demand further investigation, as we have found that some samples deviate the ray of polarized light to the right and others to the left.

By saponification castor oil yields several fatty acids, one of which appears to be _Palmitic Acid_. The prevailing acid (peculiar to the oil) is _Ricinoleic Acid_, C₁₈H₃₄O₃; it is solid below 0° C., does not solidify in contact with the air by absorption of oxygen, and is not homologous with oleic or linoleic acid, neither of which is found in castor oil. Castor oil is nevertheless thickened if 6 parts of it are warmed with 1 part of starch and 5 of nitric acid (sp. gr. 1·25), _Ricinelaïdin_ being thus formed. From this _Ricinelaïdic Acid_ may easily be obtained in brilliant crystals.

As to the albuminoid matter of the seed, Fleury (1865) obtained 3·23 per cent. of nitrogen which would answer to about 20 per cent. of such substances. The same chemist further extracted 46·6 per cent. of fixed oil, 2·2 of sugar and mucilage, besides 18 per cent. of cellulose.

Tuson in 1864, by exhausting castor oil seeds with boiling water, obtained from them an alkaloid which he named _Ricinine_. He states that it crystallizes in rectangular prisms and tables, which when heated fuse, and upon cooling solidify as a crystalline mass; the crystals may even be sublimed. Ricinine dissolves readily in water or alcohol, less freely in ether or benzol. With mercuric chloride, it combines to form tufts of silky crystals, soluble in water or alcohol. Werner (1869) on repeating Tuson’s process on 30 lb. of Italian castor oil seeds, also obtained a crop of crystals, which in appearance and solubility had many of the characters ascribed to ricinine, but differed in the essential point that when incinerated they left a residuum of magnesia. Werner regarded them as the magnesium salt of a new acid. Tuson[2119] repudiates the suspicion that ricinine may be identical with Werner’s magnesium compound. E. S. Wayne of Cincinnati (1874) found in the leaves of _Ricinus_ a substance apparently identical with Tuson’s ricinine; but he considers that it has no claim to be called an alkaloid.

[2119] _Chemical News_, xxii. (1870) 229.

The testa of castor oil seeds afforded us 10·7 per cent. of ash, one tenth of which we found to consist of silica. The ash of the kernel previously dried at 100 C. amounts to only 3·5 per cent.

=Production and Commerce=—Castor oil is most extensively produced in India, where two varieties of the seeds, the large and the small, are distinguished, the latter being considered to yield the better product. In manufacturing the oil, the seeds are gentry crushed between rollers, and freed by hand from husks and unsound grains. At Calcutta, 100 parts of seed yield on an average 70 parts of cleaned kernels, which by the hydraulic press afford 46 to 51 per cent. of their weight of oil; the oil is afterwards subjected to a very imperfect process of purification by heating it with water.[2120]

The exports of castor oil from Calcutta[2121] in the year 1870-71 amounted to 654,917 gallons, of which 214,959 gallons were shipped to the United Kingdom. The total imports of castor oil into the United Kingdom[2122] in the year 1870 were returned as 36,986 cwt. (about 416,000 gallons), valued at £82,490. Of this quantity, British India (chiefly Bengal) furnished about two-thirds; and Italy 11,856 cwt. (about 133,000 gallons), while a small remainder is entered as from “other parts.” In 1876 the imports were 79,677 cwt., valued at £133,838.

_Italian Castor Oil_, which has of late risen into some celebrity, is pressed from the seed of plants grown chiefly about Verona and Legnago, in the north of Italy. The manufactory of Mr. Bellino Valeri at the latter town produced in the year 1873, 1200 quintals of castor oil, entirely from Italian seed. Two varieties of _Ricinus_ are cultivated in these localities, the black-seeded Egyptian and the red-seeded American; the latter yields the larger percentage, but the oil is not so pale in colour. The seeds are very carefully deprived of their integuments, and having been crushed, are submitted to pressure in powerful hydraulic presses, placed in a room which in winter is heated to about 21° C. The outflow of oil is further promoted by plates of iron warmed to 32-38° C. being placed between the press-bags. The peeled seeds yield about 40 per cent. of oil.[2123]

All the castor oil pressed in Italy is not pressed from Italian seed. By an official return[2124] it appears that in the year 1872-73 there were exported from Bombay to Genoa 1350 cwt. of castor oil seeds, besides 2452 gallons of castor oil. There are no data to show what was exported from the other presidencies of India in that year.

=Uses=—Castor oil is much valued as a mild and safe purgative; while the commoner qualities are used in soap-making, and in India for burning in lamps. The seeds are not now administered. The _leaves_ of the plant applied in decoction to the breasts of women are said to promote or even to occasion the secretion of milk. This property, which has long been known to the inhabitants of the Cape Verd Islands,[2125] was particularly observed by Dr. M’William about the year 1850. It has even been found that the galactagogue powers of the plant are exerted when the leaves are administered internally.

[2120] _Madras Exhibition of Raw Products, etc. of Southern India_,—Reports by the Juries, Madras, 1856. 28.

[2121] _Annual Volume of Trade and Navigation for the Bengal Presidency for 1870-71_, Calcutta, 1871. 119.

[2122] _Annual Statement of the Trade, etc. of the U.K. for 1870._—No later returns.

[2123] H. Groves, _Pharm. Journ._ viii (1867) 250.

[2124] _Annual Statement of the Trade and Navigation of the Presidency of Bombay for 1872-73_,