Chapter XXIV: Section I: History of the Yellow Fever (5)

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.

[164] Medical Repos. vol. i, p. 170.

[165] Medical Repos. vol. ii, p. 313.

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....

[166] Account of the Bilious Yellow Fever, p. 107.

[167] Med. Repos. vol. i, p. 171.

[168] Haygarth’s Sketch of a Plan to exterminate Casual Small Pox,
vol. ii, p. 270.

“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_.”

These facts are of the utmost importance in determining the nature of contagious diseases. In conjunction with others, they show that such diseases originate in the blood, and from thence are communicated to the rest of the body. They show also, that the contagion is in all cases truly _specific_, and _immutable_. Thus the contagion of the small pox, whether existing in the matter of a pustule, in the smoke of burning clothes or paper, or in the effluvia of blood, is invariably the same, and never produces any other disease. It is the same whether applied to the human body, or to that of a brute animal; of which we have a remarkable instance in the Medical Repository, vol. i, p. 258. “A peasant of the county of Essex, in England, seeing a great many children carried off by the natural small pox, was desirous of inoculating his two boys; one nine, and the other twelve years old. Not being able to employ a surgeon, he collected the scabs of a child then sick of the disease, powdered them, and sprinkled the powder upon slices of bread and butter. The two sons ate them, and gave a bit to the house-dog. They had a mild small pox, and got well without any remarkable accident. The dog remained sick for two or three days, drank a great deal, and refused to eat: on the fourth he had a very decided variolous eruption: on the ninth the pustules were full ripe, and dried up and fell off like those of the two children. An English author says he has seen the same epidemic in a flock of sheep, the greater part of which were infected, and communicated it to two cows, one of which died. The symptoms that manifested themselves in these animals in the course of the disease were in every respect the same as in the human species.”

This instance, partly quoted in the former part of this treatise, likewise is a strong proof of the contagion of small pox being first communicated to the blood; for, by swallowing it along with the aliment, it would, in the common course of digestion, be absorbed by the lacteals, and enter the blood with the chyle. The experiments with dogs made by M. Deidier, of which an account is given p. 268, show that the contagion of the plague is equally specific with that of the small pox; and we see that it acted in all cases in which it was tried by being mixed with the blood. Being thus first mixed with the blood, it is plain that the contagion must have passed from this fluid to all the other parts of the body; and, if diseased blood is capable of communicating its disease to all the sound parts of the body in which it circulates, we must own that this strongly corroborates Dr. Waterhouse’s suspicion, “that the blood is capable of producing the infection before the disease is so far advanced as to be apparent on the surface.” If the disease originates in the blood, the latter should indeed seem more capable of communicating it at first than afterwards; because we must suppose that the diseased parts would be thrown off to the surface, and so pass off altogether. On this subject Dr. Waterhouse also quotes the opinion of Dr. Holyoke of Salem, “who, for his learning, professional abilities and integrity, is justly esteemed one of the first physicians in this country, and whose extensive practice has afforded him ample experience in the small pox.” He writes to Dr. Waterhouse, “that, although he has reason to believe that an infected person seldom gives the disease till after the eruption is considerably advanced, yet there are facts which make it probable that it is sometimes communicated earlier.”

In the same letter Dr. Waterhouse gives other instances of the inconceivable subtilty of variolous contagion, no less remarkable than those already mentioned. One is of Dr. Brattle, who, having visited patients infected with the small pox, “used the common precaution of covering his clothes with a loose gown, &c. but neglected his _wig_. In consequence of this small neglect, after riding six miles on horseback, he gave the disease to a person in a room through which he passed, where he did not stay to sit down.” Another is, if possible, still more remarkable: “David Anthony, esq. one of the overseers of the small pox in Rhode Island, after going into the hospital, and using the common precautions, neglected to _smoke his wig_. In his way home, two miles from the hospital, he called at the house of his daughter. He did not dismount, but sat on his horse, and talked to her through an open window; and, at the common period (by which we usually understand about fourteen days) she took the disease and died. Many such instances, adds the Doctor, could I relate, where wigs have given the infection, after being exposed to the open air during the passage of several miles.”

From all this it appears how difficult a task they undertake who contend for the domestic origin of the yellow fever, without contagion. In all cases they must have recourse to something visible and obvious to the senses. Thus putrid beef, putrid fish, ponds of water, marshes, &c. are all easily seen, and we are able to prove their absence as well as their presence. But we certainly know that the yellow fever has arisen where none of those supposed causes have existed, as in the Busbridge Indiaman; and, on the other hand, all the supposed causes have existed without the production of any fever. Of this last Dr. Chisholm, in the conclusion of his defence against Dr. Smith, gives the following remarkable instance:[169] “During a considerable part of the years 1776 and 1778 my duty led me very much to reside in New York; and during my residence, particularly in the summer and autumn of 1778, which were remarkably hot, and insufferably so in the lower streets of New York, no disease of a very alarming nature, and none which assumed the form of an epidemic, appeared among the troops or inhabitants. The smell from all the ships, and from those in particular delineated by Dr. Seaman (who has written a treatise on the subject) was in the highest degree offensive. The police at that time was by no means strict: putrid substances of every description were accumulated in the ships, and in many parts of the city unconnected with wharves, and yet no disease was the consequence.”

[169] Med. Repos. vol. ii, p. 291.

Some particulars above related may perhaps appear, to those who deny the existence of contagion, in rather a ludicrous point of view. It is indeed too common for people to laugh at what they cannot answer; but if we consider the instantaneous and inexplicable action of the poison of serpents, and in how little time they produce a mortal disorder, or even death itself; when we consider that contagion is only a volatile poison, and that it for the most part takes up an incomparably longer time to bring on death than the bites of some venomous animals; we cannot be surprised that a quantity of this volatile matter inconceivably less than that of animal poison should be capable of bringing on the disorder; for the length of time may be supposed to make up for the deficiency of quantity. Yet, if we consider the extreme activity of some animal poisons, the wonder at the small quantity of contagion necessary to produce a deleterious effect will in a great measure cease. In the former part of this treatise it has been observed, from Dr. Mead, that the whole quantity of poison emitted by a viper, when it bites, does not exceed the bulk of a _good drop_. An ordinary drop from a vial weighs half a grain, so that we cannot suppose a large drop to be more than a whole grain. But there are instances in which effects equally deleterious are occasioned by the bites of animals the whole bulk of which is scarcely equivalent to that of the poison of the viper. In the northern climates of the Old World, _spiders_ do not grow to any remarkable bulk, yet the bite of the poisonous spider of Russia is as mortal as that of the rattlesnake.[170] The effect of the _furia infernalis_ of Linnæus is still more to our purpose. It is an insect found in the forests of Kemi in Lapland, and likewise in Sweden and Russia; and, if we can give credit to Mr. Pennant, in some of the Western Islands of Scotland. This insect falls down out of the air, and, if it happens to light upon any uncovered part of the human body, it almost instantly penetrates down to the bone, occasioning the most excruciating pain, and death in a _quarter of an hour_.[171] Now, should we suppose the whole body of this insect to be poison, as it is probable that it is not, it is so minute, that though the whole were volatilized into contagion, it might be well supposed to adhere to a _wig_, or even a more diminutive part of the clothing; and, considering the virulent effects of even this small quantity of contagion when concentrated, it would easily follow by fair calculation, that a very _minute proportion_ of even this _small quantity_ might bring on a dangerous disease.

[170] See Medical Annals, vol. iii, p 400.

[171] The following account of the poisonous insects of Russia,
extracted from Dr. Guthrie’s letter to Dr. Duncan (Med. Annals vol.
iii, p. 396) may be not unacceptable to the reader: “I have lately
seen (says Dr. Guthrie) a woman with her hand and arm in a most
violent state of irritation from the lodgement of the lumbricus
melitensis, a worm not much thicker than a horse-hair which had
entered her thumb whilst at work in a marshy spot, and was, when
I saw her, a day after the accident, on its way up the arm, with
excruciating pain. I must own that I should not have known the nature
of the disease, if a fellow-peasant had not immediately declared
that it was produced by the dangerous worm; which many of these
people are acquainted with to their cost, as an inhabitant of the
stagnant pools and marshes in that district, about sixty versts to
the southwest of Petersburgh. I must farther acknowledge, that I was
happy to hear the patient was to be instantly transported to another
village, where a famous operator lived, well skilled in the art of
extracting the venomous insect; as I should certainly have gone very
awkwardly to work if I had been obliged to operate; though the simple
peasants perform it with success and safety, gradually winding the
worm round a quill, till the whole animal be extracted; a work of
much patience and perseverance. I was very sorry that duty obliged
me to be in town the same evening, a drive of sixty versts. It was
therefore impossible for me to accompany the patient, though I was
very desirous of witnessing this village-operation.

“But Russia is pestered with a still more dangerous worm; the furia
infernalis. It is still smaller than the former, not being thicker
than a human hair. This infernal insect, from its extreme lightness,
is often carried up into the air, with the dust, by whirlwinds; and,
if it unfortunately falls on the uncovered part of a man or beast, it
enters the flesh in an instant, and soon proves mortal, if a remedy
be not quickly applied.

“Our new vice-governor of Petersburg lately came down from Siberia,
where he was commandant of a fort. He tells me, that in the district
of Nerchinsk, where he commanded, the peasants, as well as their
cattle, are often destroyed by an insect falling upon them. To
prevent this accident from proving fatal, the part is instantly
scarified, and rubbed with a mixture of snuff and sal ammoniac.

“This I am convinced must be the furia infernalis; more especially as
he assured me, that the insect was so very minute, that none of the
peasants had ever seen it when it fell upon them, and that they had
no idea of its nature and form. But one circumstance of his, recited,
almost staggered my belief; that the carcase of an animal killed
by this insect is almost as dangerous as the insect itself. This
phenomenon I cannot account for in any other way but by supposing,
as the accident always happens in the hot months of the year, that a
high degree of putridity is produced by the venomous worm, when the
case proves fatal.

“I informed the vice-governor of the manner in which the Dalecarlian
peasants in Sweden treat the accident, in order that he might
communicate their mode of cure to his Siberian acquaintance, which
is merely applying to the part affected a piece of sweet curd. The
insect possibly prefers this to flesh, and leaves the one for the
other. I am, however, much afraid that this simple remedy will seldom
be at hand in Russia, as the peasants are unacquainted with the use
of rennet, but prepare a sour curd by means of heat, throughout the
whole empire; evidently taking its origin in the Tartar Koumis, and
shewing them to be a people of Scythian extraction. They likewise
separate butter from milk by heat, instead of the churn; a curious
circumstance probably unknown to you before.

“These two dangerous insects are, however, not all which threaten
the life of man in this empire: the southern provinces are infected
with a third, the bite of which is as mortal as that of the deadly
rattlesnake, if the part be not instantly scarified, and rubbed
with fresh butter. This is a species of crab-spider, the phalangium
acaroides, resembling the tarantula, but rather thinner and smaller.
It however kills and devours that formidable spider in a few minutes,
which, when compared with it, is an innocent animal.

“Your acquaintance, Mrs. Guthrie, lately returned from a tour on
account of health, along the north shore of the Black Sea. Among
much important and curious information, she gave me some account
of the cure employed for the bite of this mortal spider, which
finds many lurking-places among the ruined buildings of the ancient
Chersonesus Taurica, or Crimea, laid waste in the last Turkish war.
It is a curious fact, that animal oil counteracts the venom of the
spider tribes, as vegetable oils do the venom of serpents. I suspect,
however, that either of them would counteract both poisons; indeed, I
think we have a proof of animal oil acting wonderfully on serpents,
in the anecdote related by Bruce, when the deadly cerastes, or viper
of the Nile, turned away its head from the oily breast of the prime
minister of Fenaar, when he carelessly took it up in his hand, and
applied it to his naked bosom, to show Mr. Bruce how innocent it was
to men of his colour, whose very skin sickened the animal, and made
it avoid all contact.”

Lastly, it may be urged on the side of contagion that, when a vessel arrives from a sickly country, it is no proof that she has not brought a disease with her, that the people aboard are in health. There is abundance of evidence that very dangerous maladies may be communicated by those who do not labour under the same. The prisoners at the Oxford assizes were not sick at the time they communicated a dreadful distemper to those around them. Dr. Brattle and Mr. Anthony were in perfect health when they communicated the contagion of the small pox, yet the effect was not less fatal. In short, _contagion_ being a power certainly known to exist, though invisible and imperceptible, it is impossible ever to prove that it is absent; neither after the contagion of any disease has once got into a country can we be assured that it may not revive. The experience, we may say, of the whole world testifies that it does adhere particularly to clothing. Dr. Lind thinks it may adhere to the timbers of ships; and there is the greatest reason to believe that it may also adhere to the walls of apartments in houses. The appearance of fever therefore without any new importation cannot prove that it has not arisen from contagion. But it is now time to state the evidence on the opposite side.

In Webster’s Collection we find the domestic origin of yellow fever supported by Drs. Valentine Seaman, and E. H. Smith of New York; and by Drs. Taylor and Hansford, and Dr. Ramsay of Norfolk. Dr. W. Buel of Sheffield has also given an account of a fever, but so unlike that of which we treat, that what is said of the one cannot be applicable to the other.

The arguments used by Dr. Seaman are, 1. Several persons were infected, who had taken the utmost care to avoid all communication with the sick, who had not been for several weeks out of their houses, or within _eighty_ feet of an infected person. 2. The nurses and attendants in some places were infected, but in others generally escaped. Neither did the disease spread into the country, as was reported; the Doctor having inquired into these reports, and found them groundless. 3. Dr. Lining says in his letter to Dr. Whytt,[172] “If any person from the country received it in town, and sickened on his return home, the infection spread no further, not even to one in the same house.”[173]

[172] See p. 387.

[173] The same physician, in the very letter quoted by Dr. Seaman,
says that all the times this fever had appeared in Carolina, the
origin of it was evidently traced to some vessel arrived from the
West Indies.

Several other arguments of the same negative kind are adduced, which, being not essentially different from those already quoted, it is needless to detail. The following are rather of a different nature: 4. Some contagions are propagated by contact only, others at a distance; but at any rate we may suppose that contact will propagate contagion more readily and more powerfully than any other mode that can be imagined. Yet multitudes of dissections have been made, and those who made them are still alive. 5. “Specific and acknowledged contagions all seem to arise from themselves only: hence it would be almost as hard for me to believe that the siphylis, small pox, or measles, could be produced from any other cause than their own proper virus, obtained from persons affected with the like disease, as it would be for me to conceive of the formation of a plant without its having received its seed, or _radical_, from one of the same nature.[174] Contagions seem to fix in the soil of our bodies, and there seed, as naturally and regularly as vegetables do on the earth. But the yellow fever has been produced from _other causes than contagion_.[175] Does it not then admit of a doubt, whether it _can possess_ a power of propagating itself?” 7. Contagions respect no persons, but all of every clime and colour are equally attacked with them; but the yellow fever is known to attack some much more readily than others. 8. Contagious diseases generally have a determined time of invasion after an exposure to their cause: but the advocates for contagion in the yellow fever cannot be confined in this manner. “Their doctrine requires that it (the contagion of yellow fever) be permitted to act at any time between that of the exposure and the sixteenth day; otherwise it would not embrace cases enough to give it a currency.”[176] 9. “Contagions act more or less at all places and seasons, simply of themselves, without the aid of any particular circumstance of air or climate; but the supporters of the yellow fever being contagious are obliged, _by the force of the foregoing observations_, to acknowledge their _imaginary fondling_ to be but a _half-formed monster_, and perfectly inactive without being assisted by the concurrence of a predisposing constitution of the air. (Rush on yellow fever.) This fever exists only in warm weather: hence its cause in this city (New York) was perfectly extinguished by the frosty nights in the 10th month. It is confined mostly to low situations in thick-settled places; otherwise our almshouse and the surrounding country would have sadly experienced its deleterious effects.”

[174] Arguments of this kind involve us in an endless dispute
similar to that relative to the _equivocal generation_ of plants
and animals; that is, the production of plants without a seed, and
animals without parents. As some diseases are confessed to arise
from some kind of seed, we are puzzled to account for the origin of
the _first_ disease of that kind. Nevertheless, as these diseases do
exist, the difficulty arising from a consideration of their origin is
overlooked. In the yellow fever, which is not of so long standing,
the origin is more disputed. But it is likewise undeniable, that some
contagious distempers (the itch particularly) though capable of being
propagated by contagion, may yet arise from want of cleanliness, and
living on particular kinds of food. May not this also be the case
with the yellow fever? And is it not the safe and rational way to act
as though it might not only be produced at home, but imported from
abroad?

[175] This is the very point in question; but our author, instead of
enumerating the facts by which his position may be supported, refers
to Dr. Lind, whose evidence shall be afterwards considered.

[176] No greater latitude, or very little more, is required by
the advocates for the contagious nature of the yellow fever than
Dr. Seaman must allow in a distemper which he himself owns to be
contagious. It is well known, on the eastern continent at least,
that a gonorrhœa will come on at any time between the first and
_fifteenth_ day after the infection is received. Dr. Guthrie supposes
the time intervening between the reception of pestilential contagion
and the appearance of the symptoms to be four days; and Dr. Chisholm
thinks that in the Boullam fever it is somewhat short of two days:
but it is plain that much must depend on the quantity of contagion,
and the predisposition of the body to receive it.

This argument merits a particular consideration, as involving a question of very great importance, namely, concerning the constitution of the atmosphere, which we have had occasion formerly to speak of, and which is by some thought to be sufficient of itself to produce epidemics, without the intervention of any other cause. This constitution of the atmosphere is, it is true, something _unknown_; and, when people appeal to it, it is only in other words owning their ignorance; but the necessity of recurring to some cause imperceptible by our senses has in all ages been obvious. So much indeed has been said in this treatise on the causes of plague (which may apply also to yellow fever)[177] that more would be superfluous, even if our limits would admit of it. The dilemma (and it is equally insoluble let us say what we will) stands thus: If the yellow fever is produced by the effluvia of marshes, by putrid streams, or by any thing else, how comes it to pass that it has been so frequent in the United States since the year 1792 in comparison of what it was for 30 years before? Have the American cities all at once become sinks of filth and nastiness? Have the seasons been changed, or have the inhabitants given themselves up at once to swinish intemperance and gluttony, devouring, like savages, their meat half-rotten, half-roasted or half-boiled? From some declamatory publications indeed one might be apt to think that the authors certainly meant to bring such accusations against them. But it undoubtedly will be found an hard matter to prove that the general cleanliness of the country is inferior to what it was, or that the people are less virtuous than they were before. Besides, has not the vigilance of the magistrate, ever since 1793, been exerted to the utmost to procure a removal of those nuisances from which the disease might be supposed to arise? Yet their efforts have not availed; for it is confessed that the attack in 1798 was the most severe ever experienced. If cold could have exterminated the disease, certainly the three last winters have been abundantly sufficient to do so; yet it is certain that cases of the fever did appear in the end of December last, when the cold must certainly have been deemed sufficiently intense to put a stop to putrefaction of every kind. No wonder then that people, unable to see the causes of these things, should have recourse to something invisible, which they called the _constitution of the atmosphere_. On this subject Dr. Haygarth of Chester makes the following objections to the commonly received opinions concerning epidemic constitutions of the atmosphere:[178]

[177] See p. 166, & seq.

[178] Sketch of a Plan to exterminate Casual Small Pox.

“1. Dr. Odier of Geneva, in a letter to Dr. Haygarth, writes thus: ‘I believe it would not be difficult to prove that the state of the atmosphere is in no respect the cause (of the regular epidemics of that city;) for the villages and towns which surround it do not experience the same epidemic all years as Geneva, although they are situated under the same heavens, and exposed to the same vicissitudes of atmosphere.’ 2. Sydenham conjectures that some effluvia, issuing from the bowels of the earth, produce epidemics. Were this true, it might advance one step towards a solution of the difficulty by discovering a local difference in the atmosphere. But it has never yet been pretended that any such vapour was perceived. Yet every part of the earth must be capable of furnishing it; as no portion of the whole habitable globe has been discovered where the air could not propagate the small pox.... 3. Hence we may safely conclude, that the slight variations of the same climate, and the same season, must be altogether insignificant and nugatory. What important difference of atmosphere can be supposed to exist for weeks or months together in two neighbouring villages, or in the adjacent streets of the same town? This remark is plainly applicable to the propagation of the plague and other infectious distempers. Yet the latest and most respectable authors continue to be misled by this groundless hypothesis.”

Objections of this kind do not solve the difficulty. The excessive disparity of seasons with respect to the spreading of epidemic diseases, the long cessation of them at some times, and their sudden revival, as if with redoubled fury, at others, indicate the operation of some cause invisible to us; but whether that cause resides in the earth or in the air, cannot easily be known. As contagious matter seems to operate by being received with the air into the lungs, it would seem rather probable that the ultimate cause of epidemics resides also in the air. Dr. Haygarth complains that the _vapour_ arising from the earth, supposed to produce epidemics, should be invisible; but the contagion of the small pox, or of any other infectious disorder, is equally so. It must, he says, be diffused all over the earth. The electric fluid is so; it issues from the earth in every part of its surface, as is demonstrated by the common experiments of electric machines; and there are the strongest reasons to believe that it issues at some times and in some places in much greater abundance than others. But enough has been said on this subject; we must now consider matters a little more obvious.

Though it is not easily seen in what manner the proportion of the ingredients which compose the atmosphere can be changed, and we are unable to discover the operation of the more subtile fluid contained in it, yet we are certain that its constitution must be different in different parts of the world. Islands, from their being surrounded on all sides by the sea, must of consequence have an atmosphere considerably different from that of the internal parts of continents, where the air always passes over large tracts of land. Hence the continent of America, being situated between the two vast oceans called the _Atlantic_ and _Pacific_, must possess a constitution of atmosphere considerably different from that of the Eastern. Of consequence, the diseases of Europe and Asia, when transplanted to America, or to the American islands, will probably, sooner or later, assume a type different from that which they had in their own country. Dr. Waterhouse has taken notice of this in his letter to Dr. Haygarth, and thinks that it may hold good even in the small pox. “May not the small pox (says he) operate differently in the two countries? It has certainly had a different appearance, and required a somewhat different treatment, almost every time it has come among us. That the difference in the virulency of the small pox, observed at different periods, when epidemic here, may be attributed to a peculiar constitution of the atmosphere, no one seems to doubt; and why may not the difference, so reasonably to be expected between the atmosphere of your island and this continent, allow us to suppose that there is some difference in the facility of receiving the infection?” This is also an important consideration, and may throw some light on the cause, as well as the mode of prevention, of this disease.

Lastly, Dr. Seaman attempts to disprove the authenticity of some cases which have been brought as positive proofs of the disease having been received by infection. These belong not to us to consider; it being impossible, by reason of the invisible nature of contagion, to determine from a simple consideration of any patient’s case whether it was infectious or not. Dr. Fordyce has laid down the proper rule for judging in such cases.[179] One only of the instances brought by Dr. Seaman therefore we shall mention, and that, not because it proves any thing, but on account of its singularity. “Daniel Phœnix, city-treasurer of New York, is supposed without doubt to have taken his complaints from contagion: the corporation, some time past, having issued into circulation, for the accommodation of the inhabitants, a great number of paper penny bills, it has been concluded that he must have received contagion through the medium of some bundles of these bills, which he opened, that had been nearly worn out, to be exchanged, and which he opened and examined to ascertain their amount some days after he had received them.” The Doctor allows that he might have been infected by the bills, but ascribes it to putrid effluvia.[180]

[179] See p. 169.

[180] Dr. Seaman, having at last, as he thinks, completely overthrown
his adversaries, and ranked himself with the _more considerate_ and
_reasonable_ part of the community, likens those who differ from him
to such as believe in the _power of imagination_ to mark the child
in the womb; and which he is of opinion that the women of America
would not disbelieve, though all the physicians on the continent
were to unite in persuading them to the contrary. On this subject
the writer of this treatise is happy at having it in his power to
declare himself of the same opinion with the ladies, and to offer,
in support of their opinion and his, the following fact. A pregnant
woman, having been employed in dyeing some cotton yarn, and rinsed
it, after it had got the colour, in cold water, threw it, while wet
and cold, about her neck. It touched the skin on the back part of the
neck, and part of her arm. The woman started, shivered, and instantly
said that her child would be _marked_. It happened exactly according
to her prediction. The back part of the neck, and corresponding part
of the arm to that which the cotton touched, being covered with
purple spots in the child, exactly similar to what might have been
made by drops of the purple liquid in which the yarn was dyed falling
upon the skin. Of this fact I am as certain as of my own existence;
having been present when the cotton was dyed, having heard the woman
call out as above related, and seen the child after it was born, and
particularly inspected the marks.

Dr. Smith, in his letters to Dr. Buel, insists much on the vitiated state of the atmosphere, and is at some pains to describe the persons who were most subject to it. These, in 1795, were for the most part _foreigners_; under which denomination the Doctor comprehends those who came from other states, from the West Indies, and from Europe, or who had not been many months or years settled in the city. The number of citizens who suffered he does not suppose to have exceeded one in seven; but he remarks, that, both among foreigners and citizens, the severity of the disease fell chiefly on the poor. This mixture of different nations he accounts, and with great probability, one of the causes of the distemper. In confirmation of it he quotes Dr. Blane, on the diseases of seamen, remarking, “that it sometimes happens that a ship, with a long-established crew, shall be very _healthy_; yet if strangers are introduced among them, who are also _healthy_, sickness will be mutually produced.” The same observation is made by Dr. Rush, who, besides a general reference to the history of diseases, adds the following remarkable fact: “While the American army at Cambridge, in the year 1775, consisted only of New England-men, whose habits and manners were the same, there was scarcely any sickness among them. It was not till the troops of the eastern, southern and middle states met at New York and Ticonderoga, in the year 1776, that the typhus became universal, and spread with such peculiar mortality in the armies of the United States.”

This confirms the observation made in the former part of this treatise, when speaking of the English embassy to China. It may likewise with probability be assigned as one reason why large manufactories are generally so unhealthy. In them there always is a collection of people from many different and distant parts; and what holds good on a large scale must also do so on a smaller one. But this does not disprove the doctrine of contagion, but rather confirms it; for, if the discordant effluvia rising from healthy bodies of different _constitutions_ can _generate_ a disease, much more may we suppose the effluvia from sick persons capable of continuing and propagating it.

Now, let us consider the account, imperfect as it is, which we have been able to collect concerning the appearance of the yellow fever on the Western Continent. We have seen (p. 377, n.) that, at the time the plague was in England, five of the Americans were transported to that country; two of whom, after staying some time in England, were sent back, with other strangers, to America. This first colony having failed, another was sent; the Indians went to war among themselves, and the yellow fever is supposed to have made its appearance. Here a suspicion naturally arises, that a slight pestilential taint had been imported by some of these strangers, and that what would have been the _true plague_ in Europe or Asia, by reason of the peculiar constitution of the atmosphere in the New World, there became the _yellow fever_. The same may be said of the original importation of it into Martinico. Sauvages expressly says it was the _plague_ which was imported. Moseley and others deny that any such disease as the yellow fever exists in Siam; and indeed it seems at any rate to be a new disease. It seems _possible_ that diseases may change their nature; and Dr. Ferriar has given a dissertation on the conversion of diseases. As therefore the true plague never made its appearance in America or the West Indies, it seems not unreasonable to suppose that these countries are incapable of receiving it, but that the pestilential poison, when transported to the Western Continent, may assume a different, and in many respects an opposite, nature; the two diseases being thus like the opposite poles of a magnet, scarce agreeing in any thing but the common work of destruction.

It is needless to spend time in attempting to investigate the cause of this disease appearing at different periods. That of 1793 has been the most remarkable and the most destructive; the disease having never since that time ceased its ravages. Previous to its appearance at Philadelphia that year, Dr. Rush observes, that, “during the latter part of July, and the beginning of August, a number of the distressed inhabitants of St. Domingo, who had escaped the destruction of fire and sword, arrived in the city. Soon after their arrival the influenza made its appearance, and spread rapidly among the citizens.” The yellow fever quickly followed; for on the 5th of August the Doctor mentions his being called to his first patient. To the same purpose we are informed by Dr. Clarke that “the fever made its appearance in Dominica about the 15th of June, 1793, a few days after the arrival of a great number of French emigrants. They were not sick, and the fever had not made its appearance in Martinique when they left it. From the 1st of July to the 1st of October it was computed that eight hundred emigrants, including their servants and slaves, were cut off by this fever; and about two hundred English, including new comers, sailors, soldiers and negroes, all fell victims to it in the same space of time. Few new comers escaped an attack, and few recovered. It spared neither age nor sex among the Europeans and emigrants; and not only the people of colour from the other islands, but the new negroes who had been lately imported, were all attacked. Such as had been long on the island escaped.”[181]

[181] Medical Review, vol. iv.

These facts seem to point out one of the causes, and very probably a principal cause, of this dreadful distemper. They show very evidently that there is a connexion between war and diseases. It has formerly been attempted to point out a natural connexion between the horrid practices of men, on these occasions, and the production of disease. These investigations, however chimerical they may be reckoned, are yet supported by many facts, which undoubtedly prove that mankind cannot always maltreat and torment one another with impunity. The affair of the Black assizes, and Old Bailey session, in 1750, shows, that by confinement and bad usage the human body, without being apparently deprived even of health, may become poisonous to those around it, and produce dreadful diseases. In like manner the inhabitants of St. Domingo, having been put to the most dreadful distress, became properly fitted for spreading destruction wherever they went.[182] It is even probable that, in proportion to the degree of distress suffered by these people, the disease communicated by them will be malignant; nay, that new diseases may spring up, which cannot be treated with success by any method yet known to physicians. With regard to the disease in question, it seems plainly to have from some cause or other received an additional malignity. Dr. Chisholm says that what he calls the Boullam fever was supposed in Grenada to have been the common yellow fever of the West Indies engrafted on the jail fever. Dr. Lind, Dr. Jackson, and even Dr. Chisholm himself, agree that the former is not infectious: but from what has been already said the evidence seems to prevail in favour of the opinion that the latter is so. Should we then allow that two kinds of this fever might exist at the same time, in one city, the difficulty would be at once removed. But this has been reckoned by many, particularly by Dr. Rush, as totally inadmissible; and indeed it is a maxim consonant to general experience, that two epidemics cannot exist in one place at the same time, or that two diseases can scarcely exist at once in the human body. This however must be understood, principally at least, of acute diseases, or such as affect the whole system; for if any disease of a particular part shall take place, it does not seem impossible that a fever may be superadded to such local disease. The following considerations may perhaps throw some light on the subject:

[182] Dr. Moseley who has written at some length on the interruption
given to military operations by diseases, gives an account of general
Dalling’s expedition in 1780, where the English troops, confined
in the castle of St. Juan, in an unhealthy situation on the river
Nicaragua, were cut off by diseases; but these were fluxes and
intermittents. He doth not mention the yellow fever among them. He
tells us indeed that the troops under general Garth brought the jail
fever along with them, and that those who returned to Jamaica were
harassed with obstinate intermittents, with diarrhœa, dysentery, or
painful enlargements of the liver and spleen.