CHAPTER V.

ON VITIATED AIR.

The question of air holding in solution, an animal contagious matter, eliminated in the body of a sick person, and capable of producing the same disease, when inhaled by another, has hitherto occupied our attention.

It is now our design to treat of vitiated air, that is, an atmosphere deprived of part of its more essential principle, viz. oxygen gas, or tainted with the admixture of effluvia or gaseous products, from putrefying animal bodies, both living and dead, and from corrupting vegetable matter.

It is one of the most common, and most widely spread causes, of the most virulent and widely prevalent diseases, to which humanity is subject.

The importance of the atmosphere to the animal economy, is so very great, and its derangements so very hurtful to health, that it appears that a few observations respecting it may be useful to some non-professional readers. It may enable them to understand better the observations that are to follow on its vitiation.

The atmosphere is a fluid of an elastic nature, encompassing the globe, occupying the space comprehended from its surface, to the distance of twenty or thirty miles therefrom. It possesses weight, and it is by this property that water rises in pumps, and that mercury is sustained in the barometer. It is in constant motion, going, as it does, with the globe itself, revolving on its axis, and rushing, in counter streams, from the tropics to the poles, and from the poles to the tropics.

That portion nearest the sun becomes rarefied and lightened with the heat which it acquires:—it then rushes, by virtue of its comparative lightness, to the poles, and that in temperate regions presses forward to occupy its place.

By means of this motion, the temperature of the earth is kept pretty uniform, and it is corrected of any impure taint it may acquire.

The atmosphere is composed of two gases, oxygen and nitrogen, a small quantity of watery vapour, and a fraction of carbonic acid gas, or fixed air.

Oxygen is the agent on which its more active properties depend. The other component, viz. nitrogen, serving to dilute it.

They are united in the proportion of about seventy-seven of nitrogen by volume, and twenty-one of oxygen, the rest being made up of watery vapour, and carbonic acid gas.

The atmosphere supports combustion,—oxygen gas being the essential agent. During combustion, it is consumed, and at the end of the process, it will be found wanting,—the other gas being undiminished.

This may be seen, at least the diminution in the volume of air, by burning a candle in a large wide mouthed bottle, inverted over coloured water. As it continues to burn, the water ascends in the bottle, and occupies the place of the oxygen consumed.

Atmospheric air supports respiration, a process essential to the continuance of life. Oxygen gas here, too, is the agent on which it depends. Air, which has been once respired, is found to be deprived of part of its oxygen, from ten to twelve per cent.

Air, deprived of oxygen, or even deprived of a small portion of it, is unfit for respiration. A mouse, put into a vessel containing air, which has been robbed of that fluid, dies immediately. Put into one containing pure air, it breathes well at first, but, as the oxygen gets less, its breathing becomes laboured, it is convulsed, and shortly dies.

The air is concerned, besides, in a thousand operations, constantly going on at the surface of the earth. It gives up a portion of its component parts in an immense number, and in a considerable proportion receives bodies foreign to its constitution.

By one set of operations, it is deprived of its oxygen, and becomes vitiated by the admixture of deleterious principles. By others, again, its oxygen is restored, and the impurities removed; so that between two opposite forces, it is in general kept in a wholesome condition.

An immense number of bodies on the surface of the earth, are constantly attracting to themselves the oxygen of the air; some become what is called oxydized, as the metals, the dull incrustation which is found upon them after long exposure to the air, being an oxide, or a combination of the metal, and the oxygen of the air. Some bodies become acids, as the various vegetable juices which form their respective acids, by combination with the oxygen of the atmosphere.

During fermentation, the oxygen is absorbed, and carbonic acid is evolved. During putrefaction, oxygen is taken up also. There are many operations, too, connected with the arts, in which that fluid is abstracted from the air. The very soil is constantly acting on the atmosphere, and is, indeed, one vast and extended laboratory, where chemical processes, on a large scale, are going on without interruption. The putrefaction of the animal and vegetable materials, used as manure, is much promoted by free exposure to the air; hence one of the advantages of ploughing the land so universally adopted. The very nature of the soil is greatly altered by that process, and much of that change depends not only on the chemical processes just spoken of, but upon the action of the air itself, on the essential particles of the clod. From the surface of newly turned up soil, it is understood by intelligent agriculturists, that much gaseous or elastic vapour is evolved; and we have heard it observed by intelligent ploughmen, that one of the most delightful things is the air which arises from newly ploughed fields in the morning. It is said that it imparts an invigorating, and wholesome sensation throughout the body, and from thence to the mind.

All those processes we referred to, abstract from the atmosphere its most essential part, the oxygen gas. Did that process of abstraction go on without its being counterbalanced by others, imparting that principle to supply the place of that abstracted, then the atmosphere in the course of time would become unfit to support combustion or flame,—unfit to support animal respiration; and the consequence would be, that the surface of the earth would soon be uninhabitable, would soon be a lifeless desert. Such would be the inevitable consequence.

But a wise and a good Creator has prevented the occurrence of that catastrophe. He has so ordered it, that one department of nature shall correct the bad tendencies of the other;—he has placed a weight at the opposite end of the balance, to counterpoise and balance the glorious work of his hand. Animal life is met by vegetable life: their results are made to neutralize those of each other, and with a wisdom truly the Father’s, found in his works alone, he has made the apparently hurtful consequence of animal life, the very means for the maintenance of the life of vegetation. The results of the function of respiration so necessary to animals, are highly useful to vegetables. Those products that are hurtful are absorbed by the leaves of plants, which are analogous to our lungs or breathing apparatus, and the oxygen consumed by animals is replaced by the evolution of a large quantity of that principle.

During sunshine, plants, especially in water, give out a large quantity of that principle, as may be seen by putting grass leaves into a jar filled with water, and exposing them to sunshine. Bubbles of air soon appear, and collect at the top of the jar; they are oxygen gas.

The evolution of oxygen gas in sunshine, is the chief means with which we are acquainted, by which the chemical equipoise of the atmosphere is maintained, against the operations constantly going on, to which we alluded.

These observations relate to the chemical composition of the air, considered as one great whole.

There are many situations in which it becomes not only deprived of its oxygen in part, but becomes vitiated by admixture with foreign bodies or vapours, most detrimental to health, in short, most pestiferous. But, before pointing out the manner in which it becomes so tainted, and its unwholesome consequences, we would here point out the use of the atmosphere. By the act of respiration, air is carried into the lungs; it acts upon the blood brought there in large quantities, and spread out in innumerable vessels, forming a sort of network. The blood, upon its arrival at the lungs, is dark, grumous, and unfit for the maintenance of life, and the nutrition of the body; but, under the action of the air, it becomes florid or crimson, has changes wrought upon it, by which it is fitted to perform its various and important functions.

This chemical process gives a crimson and florid hue to the old blood of the system, and imparts a colour and other qualities to the fluid brought from the bowels, the result of digestion, which give it the character of blood. It gives to that fluid the last preparation before being converted into blood.

The heat of the body, which is above that of the surrounding atmosphere, is maintained by the chemical changes which occur between the mass of blood in the lungs, and the air to which it is there exposed. There is a constant generation of heat, which is diffused along with the blood throughout the whole system,—to supply the place of that which is ever being abstracted by surrounding bodies, among which exists a constant tendency to preserve an equilibrium of temperature.

When the atmosphere is vitiated, it is reasonable to suppose, that the changes in the blood passing through the lungs will not take place in their wonted integrity, and that, among other results, a diminution of the vital heat of the body may be experienced.

Vitiated air admits of division into different kinds:—

_1st_, Into air simply deprived more or less of its oxygen.

_2d_, Into air holding in solution, or having mingled with it, effluvia from animal bodies, living and dead.

_3d_, Into air holding in solution, or having mingled with it, noxious gases or effluvia arising from decomposing vegetable matter.

Vitiated air, of every kind, is unwholesome and favourable to the invasion of disease.

Vitiated air has been coexistent with many of the most appalling visitations of disease, which have befallen man since the creation of the world. It delights in the production of the most formidable distempers, such as are marked with extreme debility and proneness to the putrefactive character.

The plague, in its various visitations, from the time of its prevalence in Athens, as described by Thucydides and Lucretius, down to the period when it last raged in England, viz. in the year 1665, has been observed to be coincident, for the most part, with circumstances proving the existence of vitiated air: and at this day the most mortal diseases prevail, where foul air exists, whether that arises from this or that source.

The atmosphere becomes vitiated, when great numbers of men in health are crowded together in apartments too close and confined to admit of a sufficient supply of pure air for the perfect maintenance of respiration. In this case, the vitiation is effected by the abstraction of the oxygen of the atmosphere, the exhalation of carbonic acid gas, and the dissemination of effluvia which arise from the bodies of those who are confined.

The immediate effects of confinement to an atmosphere thus vitiated are, oppressed breathing, sense of great anxiety and suffering, fixedness of the eyes, and torpor, which gradually increases to insensibility; and the miserable sufferer dies bereft of sense and motion, from suffocation.

When the atmosphere is not so impure as to cause immediate death, disease of a putrid character, for the most part takes place. Typhus fever attacked those persons who survived the memorable struggle in the black hole of Calcutta.

A low form of fever used to commit great havoc in jails and other places of confinement, where prisoners were wont to be crowded together in great numbers, from the atmosphere being deprived of its more vital part, and being loaded with unwholesome emanations arising from the filthy persons, and clothes of those confined.

This disease is called “Jail Fever,” and manifests a peculiarly malignant character.

In hospitals crowded with wounded soldiers, but otherwise in health, where sufficient ventilation cannot be maintained, the same distemper makes its appearance, and is there denominated “Hospital Fever.”

In besieged towns and in camps, where the inmates are exposed to the offensive and unwholesome effluvia, commonly experienced in such situations, the same putrid disease prevails, and goes under the name of “Camp Fever.”

AIR VITIATED WITH EFFLUVIA FROM BODIES IN A STATE OF DISEASE.

Air vitiated with effluvia from bodies in a state of disease, and their excretions, has been variously denominated.

By some it has been styled “Contagious Air;” by some “Infectious Air;” and, when it is in connection with fever, “Febrile Miasm or Contagion.”

Vitiated air of this kind differs from that referred to above, in this particular, that it arises from bodies in a state of disease.

Both forms of vitiated air produce, or assist to produce, disease of the same character; but as the latter form not only goes to produce disease, but arises from disease also, it has been considered to be analogous to the contagious poisons, such as those of small-pox, cow-pox, and the like.

From the circumstance of this vitiated air arising from persons in disease, and assisting in the propagation of the same malady, it has all along been regarded as a specific contagious animal poison in an atmospheric menstruum; and thus has been created the perplexing and entangled web of confusion and vagueness that has been wove around the principles, viz. contagious poisons, and vitiated air arising from effluvia from persons in disease, and from their excretions.

From this circumstance, these principles, viz. specific contagious poisons, and vitiated air arising from persons in disease, have been erroneously classed together, and a supposed analogy has been created.

But these principles are widely different in their nature, and in the laws by which they are regulated.

The specific contagious poisons produce the same diseases as those with which the bodies, whence they arose, were affected, and them only; and their operation is marked by uniform effects, observing stated and unvarying periods. Vitiated air, of the kind under examination, though it arises from persons in a state of disease, and is sometimes known to operate in the production or propagation of the same distemper, does not always induce disease, does not induce that disease only, whence it sprung, but various others; and, in short, its effects are not uniform, and do not observe stated and unvarying periods.

The specific contagious poisons produce their peculiar diseases, as their proper and only effects, without the cooperation of other influences; but vitiated air, when the same disease extends, whence it arose, cannot be said to be causing its proper, only, and peculiar effects, as the same disease does not invariably follow its action. In general, the effluvia which proceed from a sick person, where they prove hurtful, cause the same distemper as that with which he is affected; for instance, the effluvia arising from a person affected with typhus fever, produce that disease again:—but that is not always the case, and an instance will be presently detailed, where the effluvia which proceeded from a body dead of one disease, produced another of a very different nature.

The reason that the presence of vitiated air is generally attended with the same disease as that with which the body is affected, whence it sprung, is, that there is existing at the time, a disposition to that particular malady: and the vitiated air only gives it form by acting as an ordinary exciting cause upon individuals prepared for its invasion.

It appears probable that vitiated air, unlike the palpable contagious poisons, assists in the production of that disease only which is prevailing, or to which there exists a disposition from the operation of other agencies; and it appears probable that vitiated air, whether it arises from persons affected with this or that disease, will, within certain limits, produce one disease as readily as another, the required particular disposition being present; for instance, that the effluvia from a small-pox patient will induce small-pox or typhus fever, according as there exists a disposition to the one disease or the other, and _vice versa_.

The effluvia arising from newly opened graves have been often productive of putrid fever.

The following case will shew that effluvia arising from the remains of a person who died of consumption of the lungs, and not of small-pox, produced that disease, viz. small-pox. When that case occurred, small-pox was prevailing, and doubtless, had there been existing at the time a disposition to putrid fever, that disease, and not small-pox, would have been induced by the effluvia which arose from the grave.

In September 1834, Peter Macawley, about twenty-eight years of age, gardener and grave-digger, was employed in the churchyard of Tranent. While busily digging a grave, he unexpectedly struck a coffin with his spade, and broke it open. The coffin contained the remains of an old woman, who had died of consumption of the lungs, and who had been interred about fourteen months.

There immediately issued from the coffin the most offensive effluvia, which threatened suffocation, and made him feel very unwell.

He proceeded home, and continued throughout the night very poorly, giddy, and uncomfortable. He rose next morning, and although no better, proceeded to the churchyard, gave some directions, and returned home, feeling giddy and unsteady. He was put to bed, and passed a very uncomfortable night.

Called in next morning to prescribe for him, I found him to be affected with severe pain of head, great heat and sweating of skin, and great quickness of pulse. He complained of thirst, could take no food, and was occasionally delirious. On the third day of his illness, pimples appeared over the whole surface of the body, which gradually becoming larger, assumed the form of small-pox. The pocks or pustules did not mature or fill with matter in the usual way, but continued throughout to be flat, and assumed a dark blue or inky colour.

His strength fast declined,—he became very low,—muttered incoherently to himself, and symptoms of a putrid character supervening, and the energies of the system fast failing, he died insensible about the twelfth day of his illness, of the worst form of immature, putrid, confluent small-pox I had ever witnessed.

He was a powerful, well-formed, and laborious man, was in good general health up to the moment of his being affected in the grave,—and it was not ascertained that he had been in a situation to receive infection from any other source.

Vitiated air arising from persons in a state of disease, is found in those situations only where the apartment is close and confined, where the person and clothes are allowed to remain in a state of impurity, where the secretions and excretions are left to ferment; and, in short, where no attention is paid to cleanliness, the removal of respired air, and the introduction of a fresh atmosphere. The production of vitiated air is thus only occasional, while, in the contagious diseases, the specific poisons are produced in every case of their respective diseases, and were they capable of being diffused in the atmosphere, there would be present as constantly an atmospheric contagion.

When vitiated air is produced, its removal can readily be accomplished, as daily experience, and the testimony of Dr Haygarth, given at the beginning of this work, amply prove.

AIR VITIATED WITH EFFLUVIA FROM DEAD ANIMAL MATTER.

There is still another source whence effluvia of a pestiferous nature arise. Dead animal matter, during putrefaction, exhales gases which taint the atmosphere, and render it unwholesome.

When these materials are exposed to heat and moisture, the decomposition is rapid, and the air becomes more obviously tainted than when that process is retarded by cold, breezy weather, and some other circumstances. When the decomposition takes place in the open air, and when that is kept in motion, the quantity of decomposing materials not being very great, the bad effects are not so serious.

When, however, buried along with a sufficient quantity of atmospheric air, to allow of the play of the chemical affinities, and kept there a considerable time, if they be exhumed previous to their total digestion or complete assimilation with surrounding objects, effluvia are exhaled, having the most intolerable stench, causing instant sickness, faintness, and giddiness, and eventually producing disease.

“Thus, we are told by Fourcroy, that in some of the burial-grounds of France, whose graves are dug up sooner than they ought to be, the effluvium from an abdomen, (belly), suddenly opened by the stroke of the mattock, strikes so forcibly upon the grave-digger, as to throw him into a state of asphyxy, if close at hand; and if at a little distance, to oppress him with vertigo, fainting, nausea, loss of appetite, and tremors for many hours: whilst numbers of those who live in the neighbourhood of such cemeteries labour under dejected spirits, sallow countenances, and febrile emaciation.”[5]

Footnote 5:

Good’s Study of Medicine, vol. ii. page 65.

Instances are likewise known where graves containing human bodies, long dead of plague, upon being opened, have emitted effluvia, which have produced typhus fever among the workmen.

It is probable that, in general, the effluvia arising from dead animal materials, undergoing decomposition in the ordinary way, are the common results of the putrefactive fermentation,—carbonic acid gas, hydrogen, nitrogen, &c.

These gases form various combinations; carbonic acid gas and hydrogen gas forming carburetted hydrogen, an inflammable gas, the same as is used for the purpose of illumination, and which cannot support respiration. Hydrogen unites with nitrogen, and forms ammonia, or spirit of hartshorn, which is volatile, and imparts a strong odour to the atmosphere, such as is experienced in stables and byres, producing sneezing and watering of the eyes.

Hydrogen, at its extrication, sometimes carries with it a portion of phosphorus, already contained in the decomposing body, and becomes phosphuretted hydrogen, a gas which ignites spontaneously in the atmosphere, the same that is sometimes observed in churchyards under the title of corpse-lights.

Hydrogen sometimes also unites with sulphur, and the combination is called sulphuretted hydrogen, a gas readily discovered by its offensive odour,—which it imparts to many very useful mineral waters.

These gases are discovered, not only in an atmosphere exposed to decomposing dead animal materials, but are also found in that atmosphere containing numbers of men in health, closely crowded together, and persons suffering putrid diseases, where no attention is paid to cleanliness and the removal of impurities.

A body affected with putrid disease is more liable to decomposition than one in health; and the secretions and excretions are more prone to putrefaction, and the emission of effluvia or gases.

Some facts are known, which shew that bodies, in some forms of low or malignant disease, both before and after death, possess a virulence, never found in bodies in health, or affected with disease of a non-malignant character. The worst consequences have followed wounds in the dissection of bodies recently dead of typhus fever; the introduction, under the skin, of the fluid contained in the petechiæ or black spots common in that disease, and even the washing of bandages and clothes employed in cases of mortification and the like.

In such diseases, the body becomes a very centre of contamination and virulence; its fluids become acrid and poisonous; and on the surface of the body, fluids are elaborated, which are productive of the most malignant and pestiferous effects. Whether these fluids, those virulent secretions, are ever diffused in the air, and impart to it their deadly properties, is a point of much interest, but one which cannot be entertained here.