On the subject of diet we shall take notice only of one article more, and that is, the use of warm diluting liquors. These are commonly three in number, viz. tea, coffee and chocolate. Abundance of declamations have been published against the use of these, particularly the first; but the daily experience of multitudes shows that its use, in moderation, is perfectly innocent. Indeed when people go to excess with this, as well as any thing else, bad effects must certainly ensue. Zimmerman[194] mentions a Dutch physician (Bontikoe) who maintained that tea ought to be drank in the quantity of one or two hundred cups a day! But such ridiculous excesses must make any thing destructive to health; and accordingly this practice, being opposed by Boerhaave, soon fell into disuse. Coffee has the same exhilarating virtue as tea, but must be considerably different in its qualities, as having in it a portion of empyreumatic oil extracted by the toasting, and therefore a change from tea to coffee in such as come into a warm country seems to be improper. Chocolate differs considerably from both, possessing no exhilarating virtue, or only in a small degree, but is more nutritive, and in South America constitutes a considerable part of the food. On coming into warm climates it is obvious that the increased perspiration must be supplied by a considerable quantity of diluting liquids; and such of these as the person has been most accustomed to ought to be preferred. For the rest, diluted malt liquors seem preferable to spirits and water. Cyder, though very agreeable when fresh, is apt to become vapid, and even get a putrescent taint. Perhaps a plain infusion of malt, of late found so useful at sea, might also prove beneficial at land, where proper fermented liquors cannot be had.
These modes of prevention are obviously derived from the circumstances which attend every emigrant from a cold to a warm country. The indication must be, to keep themselves as cool as possible, without debilitating the body. It was formerly a custom to use bleeding and purging when people arrived in warm latitudes; but this practice fell into disuse, perhaps without sufficient reason. Dr. Rush attests the efficacy of these remedies as preventives when signs of the disease appeared. “During the existence of the premonitory symptoms (says he) and before patients were confined to their rooms, a gentle purge, or the loss of a few ounces of blood, in many hundred instances prevented the formation of the fever. I did not meet with a single exception to this remark.” As mercury is found to be one of the best remedies, if not the only one, that can be depended upon for curing the disease after it is once formed, it is natural to think that it would act as a preventive; and accordingly we find, in Dr. Walker’s account of the yellow fever in Jamaica, an instance to our purpose. When the fort of Omoa was taken from the Spaniards, a great quantity of quicksilver was carried off by the English. One ship was loaded with it, and, the vessels containing it being broken by the shot of the ship which captured her, a number of men were employed in collecting it with their hands into buckets. Not one of these men was in the least affected with sickness, though a most malignant fever raged among the rest. Preventives of such a powerful nature, however, could not well be adopted without the advice of a physician; it being evidently dangerous for any person unacquainted with medicine to tamper with himself in this way.
When the disease happens to get into a town, it then becomes an object for every person to avoid the danger; and for this Dr. Chisholm has given such instructions as seem to be quite sufficient for any individual, and may be very easily reduced to practice. His observations may be summed up as follows: 1. To avoid going into infected houses. 2. If this cannot be done, to avoid going into the chamber of the sick. 3. If neither of these is practicable, to avoid a near approach to the sick person. 4. To avoid drawing in his breath, or that peculiar smell which issues from the bodies of the sick; and not to touch the bed-clothes. By neglecting this the person becomes affected with nausea: slight rigors and head-ach succeed in a few hours by the disease. 5. Not to touch the patient’s body or his wearing apparel, or suffer the effluvia from either to be blown upon the body. The distance at which the contagion acts is by Dr. Chisholm supposed not to exceed ten feet; but Dr. Lind thinks it may extend to fifty or sixty feet; but this must depend very much upon circumstances. The only thing that can be done in such cases is to keep at as great a distance as possible. As to the preventives commonly recommended, such as vinegar, camphor, garlic, &c. we have no accounts of their having ever been efficacious in any case; and there is not the least reason to think that they can be so.
To purify rooms or ships from the infection they have received, it has formerly been observed that fumigations with the acid of nitre have been recommended. According to the theory of Dr. Mitchill of New York, however, this mode of prevention must not only be useless but pernicious. The reason is, that according to this gentleman the disease is produced by the very acid in question. His reasoning is shortly this: Putrid substances evolve various sorts of air, two of which by combination form the acid of nitre. Neither of these by themselves are capable of producing fever, though in conjunction they are. Their combination is the acid of nitre, which the Doctor thinks is always that which produces putrefaction. Dr. Girtanner has related an experiment which seems to confirm this opinion, viz. that, having injected some nitrous air into the jugular vein of a dog, the animal died in a short time, and upon opening him his lungs were found of a greenish colour and partly putrid. Dr. Beddoes adds, in a note, that the green colour is a sign of the existence of nitrous acid, not of putridity; but, notwithstanding this, Dr. Girtanner might still have been in the right, as we cannot say that the existence of nitrous acid is incompatible with putridity. But there is not any occasion to enter into a discussion of the question, as the matter seems to be determined by facts which cannot be overthrown. Dr. Carmichael Smyth, in a treatise on the jail fever, considers the disease as proceeding from putrefaction, and “particularly the putrefaction of the perspirable matter,[195] when there is not a renewal of the application of air to carry it off.” With regard to specific contagions he thinks they can neither be carried off nor blunted, but by exposure to the open air or to a stream of water; but with putrid contagions he believes that they may be destroyed by the mineral acids in a state of vapour. The pernicious qualities of the fumes of sulphur prevented him from making any trials with that substance; but to nitre there was no such objection, and he therefore proceeded in the following manner; the subjects of his trial being the prison wards at Winchester, where the Spanish prisoners were kept, and among whom a typhus fever was making rapid progress: Having divided the wards into four parts, he removed the prisoners into three of them, took out of the fourth division all the hammocks and bedding, and had them thoroughly cleaned out. The hammock posts were well washed with diluted spirit of salt. The wards, when dry, were closely shut up, and pots placed in them at different distances, containing from half a pound to a pound of nitre, which was deflagrated by an iron heater put into each pot.[196] The wards were then shut up for some hours, and when opened were exposed to a free ventilation. The process was repeated twice or thrice, after which the prisoners were likewise cleaned; their old clothes, bedding, &c. taken away, were replaced by others, and none of these were afterwards seized with the fever.
A much more decisive experiment was afterwards made at Sheerness on board the Union hospital ship, where there were upwards of two hundred people sick of a very malignant fever. Previous to the fumigation all the ports and scuttles were shut up. “Sand which had been heated in an iron pot was then scooped into earthen pipkins, into each of which was put a small tea-cup containing about half an ounce of vitriolic acid; to which after it had acquired a proper degree of heat an equal quantity of nitre in powder was gradually added, and the mixture stirred with a glass spatula, until vapour arose from it in considerable quantity. The pipkins were then carried through the wards by the nurses and convalescents who kept walking about with them in their hands, occasionally putting them under the cradles of the sick, and in every corner where any foul air was suspected to lodge. Thus the fumigation was continued, until the whole space between decks, fore and aft, was filled with the vapour, which appeared like a thick haze.”
The first fumigation was performed in about three hours; the vapour subsided in about an hour, when the ports and scuttles were thrown open for the admission of fresh air. Mr. Menzies, the operator, perceived that even by this first fumigation the air was considerably sweetened; and on repeating the operation next day, which (now that the people were more expert) took up only an hour, such a change was made as the nurses and attendants were very sensible of, and, beginning to put confidence in the remedy, approached the cradles of the sick with less fear. The experiment was further carried on by Mr. Bassan, to whom Mr. Menzies resigned the office of conducting it; and from repeated trials it appeared that the fumigation effectually counteracted the influence of the contagion, though numbers of patients, labouring under the most malignant fevers, were received from the Russian ships of war.
The good effects of nitrous vapour used in this way is also confirmed by Mr. David Paterson, now surgeon in Montrose in Scotland. The trial took place in the prison wards at Forton. The operation was performed in the manner above related, and with such success, that a ward 57 feet long, 10 feet and an half high, and 20 feet broad, was filled in a quarter of an hour, only by means of three pipkins. The good effects were extremely obvious, and Mr. Paterson observed that in the wards which had been fumigated at night there was an agreeable smell next morning; and by this smell he was able to discover whether the operation had been properly performed or not. The same author gives several cases in which the good effects of the pure acid vapour of nitre in cleansing putrid ulcers was manifest. A third testimony of the efficacy of this vapour is given in a letter to Dr. Garthshore of London from Mr. James McGregor, surgeon to the 88th regiment, in the island of Jersey. The disease was a typhus fever, which had formerly proved very destructive; but, while the acid vapour was used, only one out of sixty-six cases proved fatal. Mr. McGregor is not only of opinion that the nitrous fume prevented the contagion from acting fatally, but that it destroyed it altogether, so that no more cases appeared. Mr. Paterson made trial of different acids, but had not completed his experiments: we are informed, however, in the Medical Extracts, that in the year 1795, near about the time that the last experiments were made upon the Union hospital ship, Morveau in France had employed, for the same purpose, oxygenated muriatic acid[197] in the form of air or vapour, with which he purified the infected hospital at Dijon; and the same method was afterwards extended to the different military hospitals by a decree of the National Assembly.
This mode of prevention seems to be established on as sure a testimony as any thing can be; but what can be said that will not be disputed? Dr. Trotter has argued in the most strenuous manner that such fumigation is not only useless, but pernicious. “The whole preservative means (says he) are comprised in the immediate removal of the sick; cleanliness in person and in clothing; fires to keep the people warm in the winter season; avoiding cold and moisture, fatigue and intoxication; and keeping the ship dry and properly ventilated.” To these he also thinks it would be expedient to add a band of music in order to keep up the spirits of the people; but, with regard to any thing else, he thinks that “a physician of a fleet, though armed with a diploma, and with the chemistry of the elements at his fingers’ ends, will find that very little has been left for him to do; whether his doctrine of prophylactics (preventives) be the vinegar of the four thieves, or the fumigations of modern physicians, under the scientific appellations of sulphureous gas, muriatic acid gas, or nitrous gas.” The Doctor was so zealous against these noxious fumigations, that he wrote to Evan Nepean, esq. at the Admiralty upon the subject. His argument was, that every possible method was taken on board of vessels to expel azote or mephitic air, by opening ports, scuttles, &c. and putting down windsails, &c. “This azote is the base of the nitrous acid: they only differ in the degrees of combination with oxygen, or what was formerly called dephlogisticated air: and in proportion to the quantity it attracts of this principle it is called azote, azotic gas, nitrous gas, nitrous acid, nitric acid. In short, Dr. Smyth’s preventive is the very substance that every intelligent officer is hourly employed to drive from the decks of his Majesty’s ships.”[198] This letter was transmitted to the commissioners for the sick and wounded for their report. The answer of the commissioners was to the full as learned as the Doctor’s letter; but they considered the experiments of Dr. Smyth and others as quite decisive upon the subject, so that Dr. Trotter was obliged to submit. The matter therefore being determined by such high authority, we must take leave of the subject, and proceed to consider the mode of preventing the disease from getting entrance into any town, or of eradicating it when once it has got in.
Among these the enacting and strictly enforcing quarantine laws certainly hold the first place. But these belonging entirely to the magistracy and police of the place cannot be the subject of any discussion here. The success of these has been so great in other countries, that Dr. Willich informs us “that some of the most ingenious practitioners of Italy and Germany are, at this moment, employed in a serious attempt wholly to extirpate this contagion (the small pox) from the continent of Europe; an object which has formerly been accomplished in the cases of the plague and leprosy.”[199] Perhaps, then, it is no improbable supposition, that, by a strict observance of quarantine laws, and attention to cleanliness, the yellow fever may be eradicated at least from the northern states, whose climates are less congenial to it than the southern.
Dr. Chisholm informs us that the general plan of prevention made use of in Grenada consists in the destruction of all small wooden buildings; obliging the inhabitants to build with stone or brick; to make spacious streets; to have the rooms of the houses as large as possible; stables, necessaries, &c. at a distance; and certain places appointed as receptacles for filth, to which it must be carried every morning; slaughter-houses at a distance from the town, &c. with a number of other particulars relative to cleanliness which it is needless to enumerate here; not forgetting the quarantines, lazarettos, &c. without which he does not think any activity on the part of the people can avail.