“I am of opinion, with others, that the exhalations or excretions of the sick are the vehicles of contagion. It is these which impregnate the atmosphere with noxious matter: they affect in like manner bed-clothes, or apparel, and every thing that can imbibe them, when in contact with the diseased body. When bed-clothes, or body-linen, but particularly silk or woolen cloth, have been exposed to these exhalations, and then heaped together for a length of time, the noxious effluvia are, as it were, multiplied, and will more certainly infect others than they did at first. The bales of goods which brought the plague to Marseilles, and affected the people that opened them so suddenly, had their virulence increased by not being duly ventilated. When the jail-fever was brought into court by the prisoners at Oxford assizes, and more lately at the Old Bailey, the fever was propagated from the clothing of the prisoners; no doubt, from being confined in impure, ill-aired cells, this infection became more virulent. The highly concentrated state of contagion, in the bales of goods, could only have been brought to that degree of virulence from the closeness of the package: it cannot be supposed that human beings could have put them together otherwise. The nurses of hospitals know well, as Dr. Lind tells us, that there is most danger of catching a fever when they pile heaps of bed-clothes or body-linen together for a few days, before it is carried to the wash-house. The washer-women at Haslar have also told me the same thing. They know when a dangerous fever is in the hospital by the bad smell of the clothes: this makes them air them abroad, till the smell is gone, and then they can wash them with safety. But, if it happened, from the hurry, that this could not be done, or if it was neglected by design, many of them were seized with the sickness. The porters and people employed in cleaning and fumigating the blankets and beds at Haslar are well acquainted with this fact, and they measure the danger by the badness of the smell. This ought to instruct every body to stand to windward of these infected substances when they are opened; as the current of air would then carry it the other way. In one of the courts of justice, the people who stood between the prisoners and a window, into which the wind blew, escaped the infection, while those on the other side were sufferers.
“In the summer of 1793, while the Orestes brig, commanded by Lord Augustus Fitzroy, lay at Plymouth, she was anchored very near and to leeward of an army transport, which had on board a very malignant fever among the soldiers. While the soldiers were moved on deck, to go on shore to the hospital, the crew of the Orestes, from curiosity, walked on deck to look at them. Such was the concentrated state of the contagion among the clothing and bedding of these troops, on bringing them from below, that eighteen people belonging to the brig were quickly seized with the same fever, the infection of which had been conveyed by the current of wind. It did not, however, extend much farther in the Orestes, from the attention of her commander. But this ought to be a caution for ships to keep clear of those that have fevers on board, as a virulent CONTAGION may be conveyed to a considerable distance.
“Dr. Lind is inclined to think that washing the bed-linen in hot water, even when first shifted, is attended with much risk; and that the noxious matter may be volatilized by the heat of the water, and affect the woman. For this purpose he has recourse to his favourite process, of fumigation, to insure the washer-woman. The heat of his fumigating furnace would no doubt dry the linen, and exhale any moisture; but our practice in the Charon (the hospital ship) was, to plunge everything as it came from the bed into a tub of hot water kept ready on purpose. The linen was washed and dried immediately after. We had in that hospital many malignant cases of typhus, and some deaths, yet no infection was ever spread there.”
Our author next proceeds to inquire into the cause of this excessive concentration of the infectious matter in fomites, or clothes, bed-clothes, bale-goods, &c. The most plausible reason, he says, that could for some time be assigned for this, “was, the generation of animalcula; the cotton or woollen clothing was said to serve as a nest for the corpuscles to multiply; and thus the contagion was thought to increase seven fold.” This theory had an effect on the practice of physicians, both as to the prevention and cure of fevers supposed to proceed from thence. Our author looks upon the hypothesis to be chimerical, because none of these animalcules have ever been made visible by the best microscopes. But there is no necessity for supposing the animalcules to be invisible to the naked eye. They may creep on the ground, or fly in the air, without being observed by us. Mr. Baker’s discovery of the insect which not only poisoned eleven hundred thousand times its bulk of water, but infected a much greater bulk of air, with its effluvia,[129] shows that such a thing may be possible; and in dubious matters bare possibility ought always to produce inquiry. If the perspiration of human bodies when confined becomes noxious, why may not that of a multitude of insects be so too? There is no necessity for supposing that an insect must be swallowed, or inhaled by the breath, before it can do hurt. What Dr. Trotter says of the variolous contagion emitted from the human body will apply equally to insects. “What has been called the insensible perspiration (says he) which arises from the surface and the lungs, we have a right to believe carries with it in solution a portion of the variolous matter which charges the atmosphere with the contagion of small-pox, even in such quantities as to impregnate the clothing of attendants and visitors; by which means it has been frequently carried to families and villages many miles distant from its source.” The smallness of size of insects can be little objection here. A skunk is but a small animal, yet it spreads its odour farther than an hundred diseased human bodies could propagate the plague.[130]
On this subject, however, we may remark, that though the nurses and attendants on hospitals measure the degree of infection by the smell, yet people are by no means safe in approaching patients about whom no smell can be perceived. We have already seen, from Dr. Fordyce, that what may be called the pure infection of fevers is not perceptible by any of our senses; and there are examples of very offensive smells issuing from diseased bodies without any contagion ensuing. Dr. Trotter tells us, that “a patient in typhus was sent from the Venerable to the hospital ship, with a fœtor about him, that exceeded any thing of the kind that ever came within the Doctor’s knowledge. After being washed and shifted, it still continued, and was perceived at a considerable distance. He died in a few days, yet nobody was infected from him, either in his own ship, or in our hospital. There was probably some peculiarity of constitution here.” In M. Deidier’s experiments, above related, the dog which eat the dressings of the plague sores, after being infected with the disease, emitted a very disagreeable odour, but we do not find that the odour was in any way infectious. In the Encycloped. Britan, art. Med. Hydrophobia, we find an account of an hydrophobic patient (and a patient who recovered) in whom the blood drawn from a vein was as black as ink, and stunk abominably, yet this stench was attended with no bad consequence. There is therefore no essential connexion between offensive smells and contagion; yet, as they are sometimes united, the absence of the smell ought not to encourage us rashly to go into suspicious places, neither ought the presence of it to deter us from venturing where we have otherwise good reason to do so.
Having given up the doctrine of animalcula, the Doctor goes on to explain the doctrine of concentrated contagion in a manner very similar to that given in this treatise, viz. from the decomposition of some kind of gas. “The fœtor of the breath (says he) perspirable matter, &c. evidently demonstrate that they differ from the healthy state. The smell, to our senses, comes very near what is called sulphurated-hydrogenous gas. Some of the fluids within the body would seem to be in some degree in a state of actual decomposition; unless we can suppose the mucous glands of the lungs secreting a fluid that taints the expired air in this manner. The decomposition of the fat, which sometimes disappears very suddenly in fevers, may give some ground for the supposition that a large portion of these exhalations are composed of hydrogenous gas. But, whether we can go thus far or not, what is separated from the body, it is plain, is more disposed to decomposition than when the body is in health. Now this process will still go on, whether exposed to the atmosphere or not, with this difference, that, by exposing substances which have imbibed the exhalations of the diseased to a free air, the noxious gases will be dissipated as quickly as they are evolved; while, on the other hand, by laying the clothes in a heap, packing them firm in a chest, or making up cloth into small bales, the gases are concentrated into a small space; and woe to the man who first inspires them. . . . Now this does not hold out an idea that the powers of contagion are multiplied, as by generation; for that would be to say, that these gases are themselves what we call the matter of infection. I would only go so far as to assert that they are the vehicles of it, till more certain experience shall determine farther.”
With respect to fumigations with nitrous acid, our author repeatedly declares that he has no confidence in them; nay, he brings instances where they seemed to have bad effects. But as the dispute about fumigation has no connexion with the true plague, nitrous acid having never been used as a preventive for it, we shall defer any farther consideration of it to the second part of this treatise, to which it naturally belongs.
We come now to the fourth and last mode of prevention, viz. a consideration of those means by which an individual, without separating himself from society, and who is daily obliged to have communication with the sick, may yet secure himself against infection. Here the means recommended are extremely various, and some of them so opposite, that we can scarce avoid suspecting them all. The misfortune is, that though a person should go, without fear, among the sick, though he should constantly take a medicine, and should never have the distemper, yet we cannot say whether the medicine did preserve him or not. Were it possible to know the particular constitution of the body which disposed some to resist the attack of the disease, attempts might be made to bring the constitutions of others to the same standard, but unfortunately our ignorance here is so great, that any attempt to alter the constitution of the body has generally proved unfortunate even in other diseases. Dr. Lind informs us, that the first Portuguese adventurers in Africa, having observed, that “such as had the good fortune to escape a fit of sickness or death, soon after their arrival, enjoyed afterwards a pretty good state of health, thence concluded, that the blood of such persons had been entirely changed by the diet of the country. Upon this erroneous principle they adopted a most fatal method of seasoning people to these unhealthy climates. They, by small quantities, frequently repeated, took away as much blood as they supposed to be contained in the body, and thus they reduced the patient to a state of extreme weakness.” From its being observed that people of delicate constitutions are less liable to the plague than others, such a mistake probably has also been made with regard to this distemper, but with equally bad success. Allen tells us from Diemerbroeck, “Phlebotomy, though mightily cried up by many of the ancient and modern physicians, yet we reject it altogether, as very dangerous and detrimental; for it appeared by experience that those who made use of it for prevention’s sake were seized with the plague soon after bleeding, wherefore we forbad it to all.” This may seem surprising, as we find bleeding so much recommended by Sydenham as a remedy; but by others it is equally reprobated; nay, Dr. Hodges tells us that he never knew but one who recovered from the disease after the use of it. Issues seem more likely, if not to prevent, at least to render the disease more mild if it should attack. They are recommended by Diemerbroeck, and Russel speaks of them as, “by some authors, represented as almost infallible.” He cannot, however, recommend them from his own experience, having never seen them opened for the purpose of preventing the plague; and he justly observes, that when habitual on any other account, they may perhaps lose their effect in this. “Multitudes (says he) of both sexes at Aleppo had issues in their arms, it being there a very common remedy in a variety of chronic disorders: but, notwithstanding those outlets, numbers perished; and I did not remark that those who had them were in any degree less liable than others to be infected.”
Tobacco has been recommended as an excellent preservative, particularly by Diemerbroeck, who writes with a kind of enthusiasm in its favour. “Being called (said he) to visit a patient afflicted with the plague, as soon as I entered his chamber I felt a most offensive smell of excrements (for he had a diarrhœa) with which I was greatly affected. Leaving the house after a very short visit, I instantly found myself seized with giddiness, nausea, and uneasiness at the heart; so that I had no doubt of my having caught the pestilential contagion. Laying aside all business, therefore, I immediately returned home, and smoked five or six pipes of the best tobacco; by the use of which all the above-mentioned symptoms so totally vanished, that I felt not the least uneasiness any more. Then, being again desirous to go abroad and visit other sick people, I took a drachm of theriaca, and from thence-forward was in perfect health. The same thing happened to me three or four times during the time of this pestilence; and without loss of time, according to the quantity of infection I supposed that I had taken in, I had recourse to the more plentiful use of tobacco, by which my health was restored. I always looked upon tobacco to be an excellent preventive remedy, and its smoke I have sometimes found useful to myself even in an incipient attack of the disease.[131]” He then proceeds to inform us of a report that in a violent plague at London all the dealers in tobacco were exempted. At Nimeguen, however, they were not so fortunate; yet of the family of the principal tobacco merchant (Thomas Peters, an Englishman) which was very large, none were infected, excepting only one servant maid, and she quickly recovered.
On this remedy Dr. Russel makes the same remark as on the issues. “The custom of smoking (says he), is universal among both men and women at Aleppo. This too, from its being habitually practised, might perhaps lose part of its prophylactic virtue: at the same time those who use it as a preservative must always be supposed in some degree accustomed to it, otherwise the violence of its operation on most persons, on their first beginning to smoke, might prove hurtful. It should further be observed, that the tobacco commonly used in Syria is much milder than the American, and that the oriental smokers seldom or never spit.”