Let us now attend to the consequences which must naturally and undeniably follow from this fact. If, in such a violently cold climate, the effluvia of fifteen human bodies could produce a heat sufficient to induce a violent perspiration, what would they not have done had they been in a climate where the heat of the atmosphere was upwards of an hundred degrees greater, or between 70 and 80 above 0 of Fahrenheit? Perhaps this was never thoroughly tried except in the black hole at Calcutta. Here an hundred and forty-six men and one woman were enclosed in a dungeon only 18 feet square, and consequently affording scarce eighteen inches square to each. This happened in a very hot climate, in the month of June; so that we cannot suppose the temperature to have been less than 80° of Fahrenheit.
On being confined in this manner, the vital powers endeavoured, by a most profuse perspiration, to send off the superfluous quantity of heat thrown into the body. This was exactly what took place with Dr. Guthrie; but, in the case of the black hole, there was, besides the quantity of heat produced by the warmth and perspiration of the body, an hundred and ten degrees more to be added, on account of the natural heat of the atmosphere. For we cannot suppose the heat at Calcutta, in a sultry evening in the month of June, to have been less than 80, which added to –30, supposed to be the temperature among the Tchutski, makes 110°. The perspiration was extremely profuse, and was soon accompanied with excessive thirst; nature being unable to supply such a quantity of liquid, or this liquid to carry off the heat from the body. The want of pure air began then to be felt by a difficulty of breathing; and Mr. Holwell, having in despair retired from the window, found the difficulty of breathing increase, attended by a palpitation of the heart. Aroused by his sufferings, he returned and was relieved by drinking some water, and having air at the window. The difficulty of breathing diminished, and the palpitation ceased; but, finding the thirst not to be quenched by water, he sucked his shirt-sleeves, which were wet with sweat, and endeavoured as much as possible to catch all of it that he could. The taste was soft and agreeable. A pungent steam was now felt like spirit of hartshorn. A number had died, and Mr. Holwell, once more rendered desperate, retired from the window, and lay down upon a bench, where he soon lost all sense. Next morning only 23 survived, of whom Mr. Holwell was one. He revived on being brought out to the fresh air, but was instantly seized with a putrid fever, as well as all the rest of the survivors. In this situation they were obliged to walk, loaded with fetters, to the Indian camp; at night they were exposed to a severe rain, and the day following to a sultry sun; yet, notwithstanding this ill treatment, they all recovered; having an eruption of large and painful boils all over the body. Mr. Holwell, however, said that he never afterwards enjoyed good health.
Another melancholy proof of the bad consequences resulting from a want of fresh air we have in the evidence given by Dr. Trotter, when the question concerning the slave trade was agitated before the British House of Commons. He deposed that the slaves were confined 16 hours out of 24, and permitted no exercise while on deck. They were kept in rooms from 5 to 6 feet high, imperfectly aired by gratings above, and small scuttles in the sides of the ship, which could be of no use at sea. The temperature of these rooms was often above 96 of Fahrenheit, and the Doctor says that he never could breathe in them, unless just under the hatch-way. “I have often (says he) observed the slaves drawing their breath with all the laborious and anxious efforts for life which are observed in expiring animals subjected by experiment to foul air, or in the exhausted receiver of an air-pump. I have often seen them, when the tarpaulings have been inadvertently thrown over the gratings, attempting to heave them up, crying out, in their own language, ‘We are suffocated!’ Many I have seen dead, who, the night before, had shown no signs of indisposition; some also in a dying state, and, if not brought up quickly on the deck, irrecoverably lost. Hence, in one ship, before her arrival in the West Indies, out of 650 slaves, more than 50 had died, and about 300 were tainted with the sea scurvy.”
A third example of the effects of want of air, though conjoined with other causes, may be reckoned the case of the Hankey, formerly related. The people there were not indeed confined as much as in the black hole, but it is impossible to suppose that there could be a proper circulation of air, and the length of time the passengers were confined might be equivalent to the violence of the cause in the case of the black hole. In the latter, however, the disease produced was not the yellow fever, but seems to have been a kind of non-descript eruptive one, more resembling the small pox, or rather Job’s disease, than any other. From Dr. Chisholm’s account of the Boullam fever also, it seems to have been more of an eruptive nature than the common yellow fever; so much, that Dr. Chisholm is of opinion that it partook “in no small degree of the nature of the true plague.” He says that in it he “did not observe carbuncles on any who died; but that in many who recovered they were numerous, large, and very troublesome.” He considered them also as a critical discharge, and the only one in this fever; but in the plague they certainly are not; neither is it at all probable that they were of the same nature with the pestilential carbuncles.
In p. [207] of this treatise it is inferred, from some experiments of Dr. Davidson and Dr. Chisholm, that the fevers in warm climates are not owing to a deficiency of oxygen in the atmosphere; but in a treatise on the yellow fever in Dominica by Dr. Clarke, we have other experiments, which, if they can be depended upon, certainly overthrow that doctrine, or at least render it very dubious. Dr. Clarke endeavoured to ascertain the purity of the air by Mr. Scheele’s apparatus, and which was likewise used by Dr. Davidson, viz. filling gallipots with flowers of sulphur and iron filings well mixed and moistened, and putting these upon a stand under a glass vessel, which was placed on a stool in a pail of water. The glass vessel was marked and divided on the outside, and, allowance being made for the space occupied by the gallipot, the water rose only one fifth in the glass vessel, after standing 24 hours. When the disease abated, it rose near one fourth; and upon many trials afterwards it never rose above one fourth. When the emigrants fled towards the mountains, where the air is very pure, they always avoided an attack of fever, or soon recovered if in a convalescent state. This is similar to what is stated by Van Swieten concerning the plague at Oczakow, viz. that the atmosphere was so loaded with some kind of vapour, that in certain parts of the town polished sword-blades were turned black. This seems to have indicated a great prevalence of inflammable or hepatic air, or both, in the atmosphere; but it is extremely doubtful whether this could produce a fever, much less the true plague. In Dr. Clarke’s experiments it were to be wished that he had examined the nature of that part of the atmosphere which was left after the absorption of the oxygen. It is by no means probable that at any rate the addition of a fifth part of azote could have rendered the air so unwholesome; and besides, we are entirely at a loss whence to derive such an immense quantity; for certainly the quantity of air which surrounds us, even for a few miles extent, is so great, that any considerable alteration in its composition could not take place without a very evident cause. The probability therefore is, that the experiments did not give an accurate statement of the quantity of oxygen contained in the atmosphere. Experiments on this subject must always be uncertain; and of all the modes of trying the qualities of the air, perhaps that with sulphur and iron filings is most liable to variation. It may vary, from the nature of the sulphur,[163] from the cleanness or the impurity of the iron filings, or lastly from the accuracy of the mixture. It is also a misfortune in this case, that though a great absorption proves the existence of a large quantity of oxygen in the atmosphere, yet a small one does not prove the contrary; for it is more reasonable to suppose that we have failed in our experiment, than that the constitution of the atmosphere has changed. Dr. Clarke’s experiments therefore cannot prove any thing, until more accurate methods of investigating these things be found out.
We must now proceed to investigate a third cause assigned for the production of fever, and that is the putrefaction of animal and vegetable substances. This hath been very much insisted on. Dr. Rush ascribes the fever of 1793 to the exhalations of putrid coffee, but allows also the distemper to have been contagious, and says, that “for several weeks there were two sources of infection, viz. exhalation and contagion. The exhalation infected at the distance of three or four hundred yards, while the contagion infected only across the streets. The more narrow the street, the more certainly the contagion infected. Few escaped it in alleys. After the 15th of September the atmosphere of every street was loaded with contagion; and there were few citizens in apparent good health, who did not exhibit one or more of the following marks of it in their bodies: 1. Yellowness in the eyes, and sallow colour on the skin. 2. Preternatural quickness in the pulse. 3. Frequent and copious discharges by the skin of yellow sweats. 4. A scanty discharge of high-coloured or turbid urine. 5. A deficiency of appetite, or a preternatural increase of it. 6. Costiveness. 7. Wakefulness. 8, Head-Ach. 9. A preternatural dilatation of the pupils. . . . Many country people who spent but a few hours in the streets in the day, in attending the markets, caught the disease, and sickened and died after they returned home; and many others, whom business compelled to spend a day or two in the city during the prevalence of the fever, but who escaped an attack of it, declared that they were indisposed during the whole time with languor or head-ach.”
Thus, according to our author, the fever of 1793 began from putrid effluvia, and was continued by contagion. But many attempts have been made to prove that putrid effluvia alone both begin and continue it. The limits of this treatise would not allow (even were it but beginning) of a particular account of all that has been said upon the subject; neither indeed is it needful. A single well attested instance would decide the matter; but we have already seen the difficulty of procuring that instance on either side. Certain it is, that we have instances of the yellow fever arising where it is not pretended that there was any considerable collection of putrid matters. In the Medical Repository, vol. ii, p. 149, we find an account of the yellow fever appearing “in a country village, near a fresh river, on low marshy ground, seven miles from Portland, so that no suspicion could arise of the disease being imported. Several other cases of yellow fever occurred in different parts of the country.” This stands on the authority of Dr. Jeremiah Barker of Portland, so that there can be no doubt of its authenticity; and though it cannot prove that the yellow fever may not arise from putrid effluvia, yet it certainly shows that it may arise without them. It does the same with marsh effluvia; for though we may, in the case of the village, suppose that the marshy ground on which it stands occasioned the disease there, yet what shall we assign as the cause of its being dispersed in different parts of the country, where there were neither marshes nor rotten beef? The proofs indeed of animal effluvia being the cause of yellow fever are so equivocal, that Dr. Davidson[164] supposes putrid vegetable matters to be more active in this way than the former. For this supposition he gives as a reason, that Dr. Rush has observed, that butchers, and those who lived in the neighbourhood of shambles, scavengers, grave diggers, and others of similar employments, escaped the yellow fever in Philadelphia. These, the Doctor justly observes, were more exposed to what he calls the gazeous oxyd of azote, than any other class; and he likewise takes notice, that sailors, who during long voyages feed on putrescent food, which might be supposed to produce a great quantity of this acid, are thence subject to scurvy, a disease not only different from fever, but entirely opposite to it. This exemption of people conversant among the dead has been also taken notice of by Dr. Mitchill,[165] who brings as an argument against the contagious nature of the disease, that “seven men belonging to the alms-house of New York were employed, during the whole of the sickly season of 1798, in putting the persons dead of the plague (yellow fever) into coffins, and though they handled in the course of their service upwards of five hundred corpses, in different stages of putrefaction, and though they were much incommoded with the pestilential quality of the air in the rooms they entered, and frequently were obliged to vomit, not one of them was so much indisposed, during the whole season, as to discontinue his employment.” This is no doubt a very remarkable fact, but in the present instance it proves too much; for if, from it, we conclude that the disease is not contagious, we must also conclude that it cannot be produced by putrid animal substances. Yet in the very next sentence Dr. Mitchill assures Dr. Currie, “that exhalations from corrupting beef and fish have excited sickness as malignant, and as deadly, as any which has occurred.” If exhalations from putrefying beef and fish have produced this sickness, why did not exhalations from putrefying human bodies do the same? and if we are assured that the latter did not, we have as little reason to suppose that the former did; unless we establish a difference between the corrupting flesh of one animal and of another, which no experience hath countenanced in the least.
The exemption of those employed in burying the dead, even in the true plague, is observable. Dr. Canestrinus supposed it might be owing to the use of garlic, which they were wont to bruise and rub their hands, face and breast with, and likewise to chew, before they entered into an infected house; but this cannot be supposed a very powerful antidote. Dr. Rush is of opinion that grave diggers escaped in Philadelphia by the circumstance of their digging in the earth; and he says also that scarce an instance was heard of those employed in digging cellars being attacked with the disease. “There seems to be something (says he) in the fresh earth, which attracts, or destroys, by mixture, contagion of every kind. Clothes infected by the small pox are more certainly purified by being buried underground than in any other way. Even poisons, are rendered inert by the action of the earth upon them. Dogs have long ago established this fact, by scratching a hole in the ground and burying their limbs or noses in it, when bitten by poisonous snakes. The practice, I am told, has been imitated with success by the settlers upon new lands in several parts of the United States.”
This reason is very plausible for the exemption, of such as work in the ground, from contagion; but it cannot do for scavengers and butchers, who by the nature of their employment are frequently exposed to steams from the vilest matters. We may, on the contrary, derive from thence a very strong argument that these steams are by no means essentially connected with contagion. We have already seen from Dr. Fordyce (p. [169] of this treatise) that contagion or infection is not the object of sense. Dr. Rush, though he doth not absolutely say that the contagion of the yellow fever hath no smell, yet informs us, that “the smell of the contagion, as emitted from a patient in a clean room, was like that of the small pox,[166] but in most cases of a less disagreeable nature. Putrid smells in sick rooms were the effects of a mixture of the contagion with some filthy matters. In small rooms, crowded in some instances with four or five sick people, there was an effluvium that produced giddiness, sickness at the stomach, a weakness of the limbs, faintness, and, in some cases, a diarrhœa. The contagion adhered to all kinds of clothing. It was in no instance communicated by paper.” From so great authority we may certainly conclude that, according to the best observation, there is an essential difference between the contagion of a disease and the effluvia of a putrefying carcase; and that, though the latter may be the vehicle of the former, and may increase its virulence, either by being partly assimilated to its nature, or by affording it a proper nidus for concentrating itself; yet that originally the one is not the other; and, though contagion may bring on a fever without putrid effluvia, yet putrid effluvia cannot do so without contagion. With regard to pure contagion, I shall here, to the evidences already produced, subjoin the testimony of Dr. Davidson, formerly quoted. “I must declare[167] (says he) I have seen the disease evidently propagated in this way (by contagion;) but in many instances it could not be traced. I have known three cases of the fever brought on by persons bathing in the sea along side the vessel, some distance from the shore, and neglecting to dry themselves properly afterwards. The seminia of the disease were here present, and, like the electrical jar charged, required only the approach of a conductor.” This shows an amazing subtilty and diffusibility in the contagion, scarcely indeed credible, if it were not known to be equally subtile in other cases. In the correspondence between Dr. Haygarth, of Chester in England, and Dr. Waterhouse, professor of medicine at Cambridge near Boston, the latter informs us, from Dr. Rand, that by burning, in a field near Charlestown, the bedding, furniture, &c. belonging to a person who had been ill of the small pox, the people who lived in the wake of the smoke proceeding from it were attacked with the small pox, and the disease spread. This is similar to an observation formerly quoted from Huxham; but the following are much more remarkable: “A vessel arrived at Charlestown from Lisbon, laden with salt, and lemons in boxes.[168] A person had the small pox on board, and the small pox officers would not suffer the lemons to be sold, without being first unpacked and the paper surrounding each lemon taken off. These papers were kept by themselves in a storehouse for several weeks; and after this, by order of the overseers, they were brought out and burnt; when, of two children playing round the fire, one, named Manning, took the disorder, and broke out at the usual time. . . .
“Dr. Rand was called to a lady, whom he found hot and feverish with a violent pain in her head and back; but he had no suspicion of the small pox. He bled her, and a Mrs. Brandon held the vessel to receive the blood, some of which spirted on her hand and arm. Next day the small pox appeared on the lady who was bled; and she was of course immediately separated from Mrs. Brandon; notwithstanding, in twelve or fourteen days, Mrs. Brandon was seized with the small pox, and died. Several other persons present were also liable to the infection, yet no one took the disease but this woman, who stood over the blood while it was running, and received some on her arm, except Mrs. Benjamins, to whom the bason of blood was handed over the bed, who also took the small pox from the effluvia of the blood. The same physician was called to the child of Manning (who was supposed to have taken the small pox from the burning of lemon-papers as aforesaid;) he found the child bleeding at the nose in its mother’s lap, who was then in the ninth month of her pregnancy. The next day the small pox appeared on the child, and it was of course immediately separated from its mother and all the family; nevertheless, in about fourteen days the mother was seized with the disorder, and not long after delivered of a dead child, which child had distinct eruptions over its whole body.”