An inquiry into the propagation of contagious poisons, by the atmosphere

The very knowledge and observation of mental distress and bodily suffering creates a depression of mind, and sickness arising therefrom spreads among the spectators, although, in other respects, they are comfortably situated, and have abundance of clothing and wholesome food.

Segur further relates:—“Consternation took possession of the soldiers of Marshal Victor, though unbroken in numbers and in spirits, after having given way to their customary acclamations on beholding their Imperial commander, when, instead of the grand column which was to achieve the conquest of Moscow, they perceived behind Napoleon, only a band of spectres, covered with rags, women’s pelisses, bits of carpet, or with dirty cloaks scorched and burnt by the fire of the bivouacs, and with feet wrapped in the most wretched tatters.”

Depression of mind favours the accession of many diseases. This was noticed when the prevalence of fever was under observation.

It has been remarked by Citois, that the colic of Devonshire and Poutou attacks more particularly those families who are suffering under that calamity.

Disease frequently makes its first appearance when friends and relatives assemble to pay the last marks of respect at the funeral of the departed. I am acquainted with several instances in which, shivering, tremors, and sense of great debility, have suddenly supervened in men in perfect health upon the “lifting” of the corpse, and upon the “lowering” into the grave, moments in which the hearts of many would seem to threaten to melt away, and in which they have proved to be the primary symptoms of fever; the other more violent and more dangerous characteristics being duly developed. A man, named Stevenson, died at Tranent last winter; the friends were assembled in the house to attend the funeral; his brother arrived from a distance, just as the body was about to be lifted, went into the apartment, apprehended he smelt infection, and instantly felt very ill. After having gone to the churchyard, and returned home, he was immediately attacked with sickness, which assumed the form of fever, and he died in the course of a few days.

The following statement, made by Dr Paris, illustrates well, how depression of mind, by affecting the system, promotes the action of poison:—

“A patient had been taking mercurial medicine, and using frictions for a considerable period, without any apparent effect; under these circumstances, he was abruptly told that he would fall a victim to his disease; the unhappy man experienced an unusual shock at this opinion, and in a few hours became violently salivated (that is, became affected with the peculiar action of mercury on the mouth).”

Besides the various causes of pestilence to which reference has been made, there are many others connected with peculiarities of climate, irrigation, soil, and habitudes of nations, of which the limits of this work will not permit an extended account. Of the peculiarities of climate, the most important are the greater or less intensity of the sun’s rays. It is found that much solar heat disposes to excessive action of the liver, and hence it is that fever in tropical regions is biliary; characterized by derangement of the biliary organs, of which the liver is the principal; that fever in the West Indies is yellow, a colour which proceeds from the dissemination of the bile throughout the body. Few persons who have remained long within the tropics are free of disease of the liver, and this is well known to be a common, nay, almost a universal complaint among soldiers who have returned to this country after many years’ service in those regions.

Another active agent in the production of disease in these climates is the great fall of dew which takes place between the setting and rising of the sun, and the extreme degree of cold which attends it. The dew begins to fall as soon as the sun gets below the horizon, and increases till about an hour or two before dawn; the cold at that time is extreme, more particularly felt on account of the great heat which is experienced during the day. The cold is the immediate cause of the falling of the dew, which is only the water that was dissipated in vapour by the action of the sun’s rays. The dew favours the action of the cold; and persons who are exposed to it, are in consequence frequently attacked with disease.

Persons unaccustomed to the heat, and ignorant or regardless of the consequences of exposure to the night air, often suffer much, and become affected with the peculiar distempers of the climate, in this manner: they lie down on the ground scantily covered, while the sun is still above the horizon, and make no provision for the cold and damp of night which is sure to overtake them.

Persons go to bed also with too few clothes, being then warm and oppressed with heat; in the night the dew falls, the cold arrives, and they are often awakened with severe rigors or shiverings; and thus fever, dysentery, and the like disorders are induced.

The winds in all latitudes are often instrumental in the production of disease. Some have been already referred to in connexion with the conveyance of vitiated air. Some are hurtful from their excessive heat, as, for instance, those blowing directly off the burning deserts of Arabia and of Africa. The Sirocco is not only extremely hot, but is copiously loaded with aqueous vapour. It visits Italy, blowing there several days at a time, and acts almost as a vapour bath upon the inhabitants. The Sirocco blows off the deserts of Africa, passing over the Mediterranean sea, there imbibing a large quantity of water, converted into vapour, and rushes upon the fair shores and degenerate population of Italy. Its immediate effect is to relax the system, and to open up all the pores on the surface of the body. These effects are very hurtful to health, and become particularly so, when they are long continued, as sometimes happens. But more dreadful are the results of exposure of persons so situated, to the sudden action of an intensely cold blast, such as the Tramontane, which, driving from the northern side of the Alps and Pyrenees, passing over their snow-capt summits, and sharing their bitterness and frost, rushes, without warning, upon the inhabitants.

The tramontane is very cold, and acting upon persons in a manner “forcing” in a hot house, soon produces pleurisies, colds, consumptions, &c. &c.

These vicissitudes in Italy, and those which are wont to occur in regions within the tropics, are much greater than the variations of weather which are experienced in the British Isles, and which are comparatively harmless; or are hurtful, at least, in a much less degree.

In many countries the rivers periodically overflow their banks and cover the surrounding territory. The Nile overflows annually, and when the water has almost disappeared by infiltration into the soil, and by evaporation, and when that which is left is muddy, slimy, and mixed with organized remains, exhalations arise, and a vitiated atmosphere is produced, which is said by medical men, who have lived upon the banks of that river, to be productive of plague.

The territory again on the banks of the Canton river in China, is almost constantly under water, and its fertility is thereby much increased. The ground there is used for the growth of rice which delights in a soil covered with water. When the heat is intense, when the water contains organized putrefying materials, and when the weather is close, and the atmosphere is a little agitated, then vapours ascend which, mixing with the air, cause it to be vitiated, and to be productive of malignant remittent fever.

The habits of nations are also influential in the production of disease. The privations and penances which devotees endure are followed by a very hurtful influence on the health, whether they be what are enjoined, or whether they be voluntarily suffered, as they suppose, to conciliate the favour of the Deity.

The diet, clothing, occupations, pleasures, government, laws, social usages, genius, and ambition of nations, materially influence their health, and give tendencies to particular maladies; but interesting as the subject is, the investigation cannot be pursued here.

It was shewn in the first part of this work, that the contagious poisons of disease, such as the matter of small-pox, are known to act in two modes only, first, by application of the palpable matter itself to a person, or by contactual contagion; secondly, by application of clothes or other such substances, impregnated with that matter, forming what has been styled fomitic or mediate contagion. It was also shewn, that their action through the medium of the atmosphere, has never been ascertained. Experiments were detailed, which were performed on those poisons, to ascertain their capability to become dissolved in the air, and their evidence was as strong as it possibly could be, against their possessing that attribute.

It was, in short, fully ascertained, that contagious diseases do not propagate by atmospheric contagion.

Contagious diseases propagate among those who expose their persons to contact with the matters or clothes impregnated with them. There are many facts of an incontrovertible character, which prove the occasional operation of the former mode at least, and to render probable, that of the latter; and hence, whatever attention is paid to cleanliness of the sick person, his apartment, and to the prevention and removal of vitiated air, persons touching a body, when there is present on its surface specific contagious poison, such as the matter of small-pox, or even handling clothes, which have become impregnated with it, incur a risk of being affected with the same disease, by means of that matter or fomitic contagion.

In all the contagious diseases (those in which there is eliminated a palpable poison, or matter capable of causing the same disease in others), their respective matters are invariably formed, and are apt to propagate in the modes specified, so that visitors and other attendants should ever be upon their guard, the first not to touch the sick person at all, and the latter not to touch more than is necessary, and to take precaution to render the risk as slight as possible.

Subjoined is a list of diseases which are known to be contagious, or to be possessed of a matter of the nature referred to, and that are therefore wont to be propagated by contact with the sick, or with his clothes.

These are almost the only diseases known in this country, which are positively ascertained to be characterized by the elimination of contagious matter, and which, therefore, there is any risk of getting by contagion. The continued fever of this country has been supposed, by some physicians, to be a contagious disease, from there being sometimes observed pimples on persons affected with it; but that is by no means an ascertained point.

Those above enumerated seem to include all the most important diseases in this country, which are capable of being propagated by contagion, acting in either of the two ways already described. Some of them are capable of affecting the same individual only once, and some affect persons as often as they are exposed to their specific contagious matters.

How comparatively small, then, is the range of contagion,—an agent which has been thought to accomplish worlds of mischief, and to destroy almost whole communities.

Visitors may approach within a very short distance of persons afflicted with these distempers, without danger of suffering, provided they do not touch the bodies or the clothes.

They have nothing to apprehend from the atmosphere, if attention is paid to the maintenance of its purity,—such as is necessary in other situations, as well as in the sick-room.

Never brought into that immediate contact with the poisons which is necessary for their propagation, they stand in need of no directions for their removal or counteraction.

Those persons, on the other hand, who are called upon to touch the patient and his clothes, are exposed to danger; and they should lessen its amount, by instantly putting their hands into warm water, and by freely washing them, with the assistance of soap,—and that ablution should be performed after each instance of contact.

I have often had occasion to feel the pulse of persons ill of the worst forms of confluent and black small-pox, and any risk that has thereby been incurred, has been removed or remedied by immediately washing the hand as directed.

In addition to washing, after that process is done, a small quantity of a strong smelling liquid, such as Lavender water or Eau de Cologne, should be poured into the hands. Their grateful odour may hide or cover that of the apartment, which the attendant may mistake for contagious air, as is often done, and thereby remove groundless apprehension. These seem to be the chief precautions that are necessary for meeting the dangers of contagion, if there is included what is sometimes used, viz. a covering for the hand,—a glove and the like,—which, as being harmless, and such as may possibly be useful, should be employed; and likewise the avoiding of eating and drinking with the same instruments and vessels used by the sick persons.

The propagation of disease by contagion, in the modes already stated, though it can take place, and though it sometimes does take place, still there are the strongest grounds for supposing it a comparatively rare occurrence.

I have already shewn, at the beginning of this work, that in one form, the atmospheric, contagion never operates, and I am now prepared to assert, that in the two forms in which alone it can act, that the instances of its undoubted agency are by no means nearly so common as they are commonly believed to be, especially in connexion with those acute diseases, accompanied with fever.

It is my belief, founded on much observation, study, and reflection, that almost all cases of those contagious diseases, arise from causes or circumstances connected with those great agencies already detailed at full length, as inductive of pestilence in general, and of a nature epidemic, endemial, meteorological, and the like.

I am led to the opinion, that this course of origin, even in contagious diseases, is the rule, and that the origin of disease, by contagion, whether contactual or mediate, is the exception. The grounds of this opinion are,—

1st, A fact well ascertained, and of which I had lately two instances, in houses contiguous. Infants neither inoculated, nor vaccinated, lie with their mothers and others ill of small-pox, and do not take that distemper.

2d, Women, while labouring under small-pox, occasionally bear children in perfect health.

The above are common occurrences, and I am in possession of the particulars of several which came under my own observation in the beginning of 1838.

These cases prove the occasional, nay, the frequent inactivity of contagious poison, even when applied in a palpable form, and in a recent condition, to the bodies even of those who are not protected against its operation by inoculation for cow or small-pox, or by a previous attack of disease; and this inactivity is observed too, when the most ample opportunity is afforded for the action of the poison, viz. while children are asleep together in the same bed, and when infants are upon the breast of mothers affected with small-pox.

Those very children who thus escape taking disease by contagion, are frequently known to be seized with that identical disease, at some future time, varying from months to years, when no other case is known to exist in the neighbourhood, and where there is no room to suspect the operation of contagion.

It is, I believe, as common as the contrary course, for small-pox, and other reputed contagious diseases, after appearing in one house in a town or hamlet, to break out in others at a distance and in different directions, and not to progress from that which was first attacked to those lying adjacent, or to spread around as from a centre.

For example, the first case of Typhus Fever which occurred in my practice, in January 1839, was at Meadow Mill, a village half a mile north of Tranent; the second case was at a hamlet called Redcoll, about four miles east; the fourth and fifth cases occurred in Tranent; while the sixth and last for that month appeared at Elphinstone, a village situated about two miles to the south-west of Tranent.

I am led also to the opinion, that the ordinary cases, even of those diseases which are known to be occasionally propagated by contagious poison, do not arise from contagion, but from other circumstances and agencies; by the history of the plague, for while that scourge is ravaging in the East, and destroying hundreds daily, it frequently ceases, immediately upon the overflowing of the Nile, which buries and covers the pestiferous soil, and the putrefying materials which had been exhaling noxious emanations.

This sudden departure or cessation of plague, upon the overflowing of the Nile, proves that contagion, though it may be the cause of some cases of that disease, is not the occasion of the vast majority,—the great mass of cases, in short, which constitute the Epidemic; and goes far to prove that distemper to be dependent upon an unwholesome condition of the soil, or vitiated atmosphere, and other widely extended and unwholesome agencies, of a nature totally different from specific contagious poison.

That fact goes to prove, in reference to one disease, viz. Plague, what I believe holds with all other contagious distempers, that contagion, at most, is only an occasional, while such influences as those to which reference has been made, are the constant and general causes of sickness.

The important part which vitiated air enacts in the production of many forms of disease, has been already fully shewn; and it must be admitted, that whatever has for its objects the prevention and correction of that principle, is deserving of attention.

By preventing the production, and by removing vitiated air when already formed, a vast amount of disease may be arrested, and much of that benefit will actually be accomplished, which it was boldly but fallaciously pronounced would revert from many absurd measures which were adopted, and which are still recommended for the avoidance of contagion, and would realize almost all the advantages which Quarantine Regulations, and the most efficient systems of Contagion Police can or propose to afford; and that, too, at no inconvenience to individuals, no restraint upon communication, after certain processes of purification have been undergone, and no ruinous hindrance of commercial transactions.

The various sources of vitiated air have been already noted. Some of them are beyond any present remedy, as the unwholesome condition of the surface of the earth in many regions, within the tropics, for whose correction or improvement, time, capital, enterprise, labour, and perhaps new climates, are essential. To that source of vitiated air, draining, cutting down superabundant wood, embanking rivers, reclaiming partially inundated land, and cultivation, must be applied before the emanations which infest these situations can be prevented from arising.

Another source of vitiated air is, men being crowded together in close and confined apartments, where no attention is paid to the preservation of cleanliness and the removal of impurities, as in some jails and other places for the confinement of criminals.

That source of vitiated air is particularly worthy of notice here, because a very common form of disease which it induces is what is well known as Jail or Contagious Fever.

The means for the prevention of this form of vitiated air are obvious. Large, airy, well ventilated and lofty apartments are essential, if many persons must be put together; and, where that is not necessary, it is advisable to have them separated in several different chambers, where due ventilation is strictly maintained, by retaining the windows more or less open through the day, or by other equally effective means.

By the sleeping of many persons in one apartment, the atmosphere is deprived to a great extent of its more vital fluid, and becomes unfit to support respiration in its integrity; and the health of the inmates is not unfrequently injured in consequence. The sleeping of many persons in one bed-room, therefore, should be avoided, where it is possible; but, where that is not practicable, it becomes necessary to lessen the evil consequences, and this may be done by keeping a door or window partially open during the night, when the weather is not too inclement to forbid that procedure.

At all times, exhalations to a great extent are proceeding from the bodies of men; and, where individuals are much confined to one apartment, and where that is small, close, and ill ventilated, they fasten or adhere to the furniture, curtains, carpets, and the very walls. During sleep, the amount of these exhalations, it would appear, is increased. It is then that the pores of the entire system, as well upon the internal as the external surfaces, are most freely laid open, and that they pour forth their respective fluids most abundantly. The quantity of watery vapour which issues during sleep from the lungs is prodigious; and the large quantity of water which is sometimes seen collected on the panes of windows in the morning, and which is condensed vapour, affords some idea of the vast quantity of fluid which is exhaled during sleep. With this watery vapour, other ingredients of a hurtful nature are conjoined, and, like it, adhere to the furniture and clothes. When these exhalations are permitted to remain, they impart to the room a disagreeable odour, cause the bed-clothes to be damp and unwholesome, which, with the progress of fermentation, at length emit offensive effluvia. In order to avoid these hurtful consequences, the following measures should be adopted. When the bed-room is left in the morning, the window or windows should be opened, and the bed-clothes freely exposed to the air for some time: the constant passing of fresh air over the clothes and through the apartment, will shortly carry off the greater part of the exhalations which may have adhered.

The window should be left open during a part of the day, if the atmosphere without is not particularly damp, as the removal of impurities, when they have adhered to solid bodies, is not effected at once, or so immediately as is generally believed.

Exhalations of a very hurtful nature proceed also from excretions, which should be removed immediately, certainly before fermentation can have proceeded to any considerable length.

The furniture of bed-rooms requires special care. The various processes of rubbing, washing, and scouring, should be frequently repeated; and articles, such as bed and window curtains, should be oftener in the washing-tub than is dreamt of by many very careful housekeepers, and when they are composed of fabrics of a nature to forbid contact with soap and water, the necessary purification may be effected, at least in a partial manner, by occasional exposure to the wind in the open air.

In those apartments in which the sick are contained, the atmosphere is particularly liable to become vitiated from the exhalations of the body, and from the excretions being in general more disposed to be virulent than those of persons in health.

The necessity for a constant supply of pure air is, if possible, increased, and the utmost care and attention is demanded, in order that this may be duly provided. In large hospitals for the reception of sick, ventilation becomes a point of the most important nature; and, when efficiently established, is entitled to be considered one of the most powerful remedies which can be obtained to check the progress of disease, and to promote recovery, when that is once established.

Various methods have been devised to promote ventilation in hospitals, which it is unnecessary to describe here; for this reason, as well as others, that the importance of ventilation is too well understood by medical men, for them not to enforce it in establishments of which they have the management.

During sickness in private houses, ventilation cannot be too much enforced. When the weather will permit, one window at least should be partially opened, pulled down, if possible, during the summer. In winter, the door of the apartment should be left open for a short time occasionally; and, if the chamber is not very small, a fire may be used, which will not only remove the cutting dullness of the air, but will also ensure a constant change of the atmosphere, from the ventilation which it causes.

In some forms of disease, as in the “Sweating Sickness of England,”—the typhus fever, the skin is wont to become covered with perspiration, which is particularly prone to undergo putrefaction. To obviate that putrefaction, and to prevent the formation of effluvia, it is proper to wash the skin of the patient, in almost every form of disease, with soap and warm water, which will purify that important organ, and assist in rectifying its functions. Where the character of the disease is putrid, sponging the skin with vinegar and water, either warm or cold, should be adopted, and is often of the greatest use.

All impurities should be removed from the sick-room, as they are liable to vitiate the atmosphere; and all clothes and utensils which have been used by the patient should be immediately put among warm water, and left there till a convenient season occur for their being thoroughly cleansed.

When the patient is in a state to bear the fatigue of being removed for part of the day to another chamber, advantage should be taken of his absence from his bed-room, to ventilate the apartment, by throwing open the doors and windows, to expose his bed and body clothes to the free action of the air, and to cover the sickly smell frequently present in sick chambers, by the burning or dissemination of some fragrant substance in the atmosphere.

CORRECTION OF VITIATED AIR.

The effluvia which are wont to arise in sick-rooms, are sometimes so very strong, especially where little attention is paid to cleanliness and ventilation, as to fasten most tenaciously to the contents of the apartments, and to impart to them a most disagreeable and sickly odour, not immediately removeable upon the establishment of currents of air obtained by opening the doors and windows.

These effluvia, for the most part, are cognizable to the organ of smell, and they have long been, and are still, vaguely designated “Contagion,” “Infection,” and the like.

Where effluvia are not recognised by the organ of smell, there are many good reasons for believing, notwithstanding that circumstance, that they may be present in rooms which contain, and which have lately contained, sick persons.

Well authenticated cases are on record, where persons in health have inhabited apartments which, at a former period, contained sick persons, and have been attacked with disease in such a manner as to leave little doubt of the presence of unwholesome effluvia, and of their having been the efficient agency in the production of the evil. These instances have occurred, where it is impossible to suppose that the effluvia could have been commingled with the atmosphere during the whole interval, often amounting to years, from the period of the removal of the sick, to that of the taking up of their abode there by those who have suffered.

The period during which the apartment has been uninhabited has, on many occasions, been too long to admit of the opinion that the atmosphere has not been again and again changed. It would therefore appear, that not only the atmosphere becomes infested, on those occasions, with effluvia, but that the walls, the furniture, and the floors may likewise become impregnated with them.

It is consonant with experience to admit, that solid bodies occasionally combine with, or imbibe, or attract gasiform products, or that aeriform or vaporic agents adhere to solid substances.

The opinion may be entertained, that the effluvia of sick rooms may fasten to the furniture, &c., and in that situation, even where ventilation is maintained, form centres from whence they may be disengaged, either constantly, for a long period, or only on occasions which are particularly favourable for their redissemination in the atmosphere.

It is common to designate these effluvia primarily disseminated in the atmosphere, and the vitiated air which is formed in old fever and plague wards, and to which reference has just been made, Contagion, without any other term to mark the distinction between these principles and those which are legitimately so called. In a previous part of this work, the distinction has been carefully made, and it was shewn that the effluvia under discussion do not form, strictly speaking, a contagious, but only a vitiated atmosphere.

As it appears that effluvia which arise from the bodies, and the excretions of the sick, do not only mingle with the atmosphere, but also adhere to furniture, walls, &c., when concentrated and long exhaled, it becomes necessary not only to remove that atmosphere in which they are disseminated, but also to adopt means for the purification of all those bodies to which they may adhere, in order that the atmosphere may not become again and again loaded with them, arising, as they may, from the places to which they are adhering.

The means best calculated to obtain that end, are those processes to which reference was made above, viz. rubbing, scouring, washing, and exposing to the free action of the air.

But besides these means of purification, there are others, as fumigations, which are calculated to be highly useful, and which should be used on all occasions of severe general disease.

Fumigations are vapours of an elastic nature, permanent and non-permanent. They are diffused through the atmosphere, and impart to it their peculiar odours.

They are highly useful. In the first place, there is reason to believe that they, especially the more active, may decompose the effluvia which are mingled with the atmosphere, and which are adhering to solid bodies, all of which they can be made to reach and act upon, and even to penetrate where the scrubbing-brush and hot water cannot be applied; in the second place, they insure a change of atmosphere; and, in the third place, they effectually cover or hide the smell of the sick-room, which is at all times highly disagreeable, and which is often regarded with great terror and apprehension, being ever associated with ideas of contagion and disease;—and in this way, fumigations are found of very great value, giving, at the same time confidence to the timid, and affording something different from what contagion is commonly thought to be, on which the organ of smell may be safely exercised.

Some fumigations are produced by the volatilization of solid bodies, as camphor and carbonate of ammonia, or sal volatile;—some by the volatilization of liquids, such as vinegar, pyroligneous acid, and the various essential oils, as cinnamon, rose, thyme, mint, pennyroyal, carraway, and turpentine, while others are permanently elastic fluids or gases, as muriatic acid gas, chlorine, and ammonia.

The first-mentioned substances, viz. camphor and ammonia, are not very strong, and may be disseminated through the apartment of the patient, even when he is present, without giving him any uneasiness. Carried about with those who visit the sick, and who are apprehensive of contagion, they are useful by affording a grateful odour, which hides disagreeable taints, and perhaps it is in that way chiefly that they are useful.

The liquids which have been named above, have been long used for the purposes of fumigation, and in general, they may be employed even in the presence of the patient. A few of them may possibly decompose effluvia, but there is much reason to think that they are useful, for the most part, by hiding ungrateful odours, and imparting to the atmosphere, which is liable to be suspected as unwholesome, a delightful fragrance.

Vinegar is much used for the purpose, and with very considerable benefit, and is therefore to be employed.

The essential oils are capable of being diffused throughout the air, and with the assistance of heat, are often made available for the purpose of covering odours. When they are to be used, the oils should be poured upon a piece of live coal, held in the middle of the apartment; they are then immediately converted into vapour. In like manner, vinegar and the other volatile liquids may be disseminated through the atmosphere.

The oils, the vegetable substances in which they are contained, tar and the like, are occasionally burnt with the same intention, and sometimes with advantage.

The incense so much used by the ancients, was procured for the most part by the burning of the vegetable substances in which these essential and fragrant oils resided, by which part of them is diffused in vapour.

The ostensible and pretended object of the priests, in offering up incense, while that and other religious rites were performing over the bodies of deceased persons, was the conciliation and propitiation of the Deity. But while this was the sole ostensible object of the priests, and that which was held by the people, as the only and exclusive purpose proposed, there is good reason to believe that the offering up of incense, like many other observances of religion, had its temporal, and worldly, as well as spiritual ends; and that the sweet smelling odours, which were thought would be so grateful to Heaven, were, on those occasions, used in no small degree, as so many fumigations, to defend the pious and resigned priests from the effluvia of the dead body, and the consequent corruption of the atmosphere.

The use of fumigations, in a disguised form, was perhaps rendered necessary, as the purpose of purifying the atmosphere, might have seemed to cast reflections or imputations on the dead, which the vile, barbarous, and superstitious people, especially relatives, might have resented with acts of violence, or which might have thrown priest-craft into contempt and abhorrence.

Perhaps it was in reference to this matter, as it was in many others of graver import, that the ignorant and superstitious condition of the people on the one hand, and the cunning, subtlety, despotism, and superior knowledge of the ministers of religion on the other, in early times, made it convenient that certain ends, thought to be desirable, should be accomplished without reasons, explanations, or intentions being given.

There is, then, reason to believe, that the burning of oils and other fragrant substances, was used in very early times to purify the atmosphere from the effluvia of dead bodies.

The products of the combustion of essential oils, tar, pitch, and the like, are carbonic acid gas and watery vapour, which, there is reason to think, cannot be useful in purifying the air, or in neutralizing hurtful effluvia.

The permanently elastic gases which are used as fumigations, are the most potent agents of the kind, and they are generally used, and with much propriety and advantage, in all cases where disease is of a putrid character, and where, in short, the atmosphere is likely to be vitiated to a great extent. They form also the most useful fumigations for the purpose of purifying the atmosphere, and the walls and furniture of apartments lately inhabited by the sick, and their employment, in such cases, should never be neglected, even when there is no great reason to apprehend vitiation of the atmosphere, for when advantage is doubtful, there can exist no possibility of detriment. The agent now most commonly employed, is chlorine gas, and it is perhaps the most efficient in the list of fumigations.

Chlorine gas has a greenish colour, and a most disagreeable and suffocating odour. Water impregnated with it, has the property of destroying colours, and chlorine is, on that account, much employed in bleaching, in the forms of “Bleaching Powder” and “Tennant’s Powder.”

When chlorine gas is disseminated through an apartment, any stench, however strong and intolerable, which may have been present there, is no longer perceptible, the odour of the chlorine taking its place, or so completely covering it, as to render it no longer cognisable to the senses.

Chlorine gas is employed both alone, and in combination with other bodies, as lime and soda.

In combination with these alkalis, chlorine forms the chlorides of lime and soda. The former is well known in this country, and the latter, when dissolved in water, forms the “Liqueur disinfectante” of Monsieur Labarraque, which is much celebrated on the Continent.

The solutions of these salts in water, are sprinkled occasionally through the apartments which are to be purified.

When these solutions are sprinkled about, and exposed to the action of the air, the chlorine escapes in its gaseous form and mingles with the atmosphere, while the lime and soda, which are now uncombined, attract and unite with any carbonic acid which may have arisen from the patient, his clothes, or excretions.

The solution of chloride or chloruret of lime, answers sufficiently well, but as it is to be obtained in all drug shops, it is unnecessary to add here a formula for its preparation.

FORMULA FOR THE PREPARATION OF CHLORINE GAS.

Take three parts of common salt, one of black oxide of manganese, and three of strong oil of vitriol. Mix the salt and the oxide together in a stoppered retort, pour in the oil of vitriol and apply a gentle heat. The gas is immediately evolved, and rapidly diffuses itself throughout the atmosphere. Muriatic acid gas, a combination of chlorine and hydrogen gases, though considered as inferior to chlorine as a fumigation, is frequently employed for the purpose of decomposing effluvia, as the materials for its preparation are almost ever at hand.

FORMULA FOR OBTAINING MURIATIC ACID GAS.

Put a handful of common salt previously made very hot into a saucer, and pour over it an ounce of strong oil of vitriol. The gas is immediately extricated.

It has been already said that the fumigations just noticed are on many occasions highly useful, and their employment is much recommended in all situations where the atmosphere is liable to be contaminated by effluvia from sick persons or from dead bodies; but it is not therefore to be understood that, because the use of these agents has been advocated, it is for the purpose of destroying atmospheric contagion, of decomposing the specific animal poisons which have been supposed to be present, and dissolved in the atmosphere, which is the object, or one of the objects, held in view by the generality of those who advise the use of fumigations. These fumigations have been recommended with the view of correcting what has been treated of as vitiated air, which is distinct from, but which has long been erroneously regarded as, Atmospheric Contagion. On some occasions, great fires of wood, coal, pitch, gunpowder, and the like, have been recommended for the purpose of destroying contagion and purifying the atmosphere. During the prevalence of the plague in London, great fires were kindled in the streets, and, according to some historians, with considerable benefit.

Such great fires produce great agitation of the atmosphere, and it is possible that in this way they may prove useful in improving the condition of that fluid, particularly when, as happened occasionally during the visitations of plague in London, the weather is sultry and close, and when the atmosphere is confined and little agitated, and allowed almost to stagnate.

There is much reason to think that the agitation of the ocean, by its waves and tides, is not more favourable to the preservation of the purity of its waters, than the movement of the atmosphere, by winds and currents, is to the maintenance of its wholesome condition, and when this is lost, to restore it; and in the absence of winds, and when pestilence is raging, the use of combustion on a large scale may with advantage be adopted; but in this climate, where the weather is seldom long calm, the occasions for the employment of that agency can be very rare indeed.

Heat is much used for the purpose of dissipating effluvia, and purifying goods, clothes, letters, &c., which are supposed to be impregnated with contagious matter, or other unwholesome impurities; and there is good evidence to shew that this agent is perhaps the most powerful instrument which is ever employed for the purpose in question.

Heat when applied to an atmosphere containing effluvia will rarefy it, cause it to become lighter, and dissipate it, amid the atmosphere above, where any opportunity is afforded for its egress; and when the heat is employed in the sick chamber, much good is effected by the dissipation of the damp and condensed vapour which cannot fail to be frequently present in that situation.

In the sick chamber, the presence of a fire for even an hour daily is highly useful where there is little opportunity for ventilation, and when the external atmosphere is damp and motionless, for the heat issuing from it, will dislodge and dissipate any effluvia which may have become condensed, and have fastened on the furniture of the apartment.

The condensation of effluvia, &c., is thus depicted in the “Mussulman.” The apartment is that of a prison. —— The pestiferous breath of the surviving was mingled with the effluvia from the dead, and the empoisoned exhalation was condensed on the damp walls, and was seen trickling down in drops of poison to the ground.^[10]