Cleanliness, in houses and dress, cannot be too often inculcated during the prevalence of a yellow fever.
Let it not be supposed, that I mean that the history which I have given of the method of cure of this epidemic, should be applied, in all its parts, to the yellow fevers which may appear hereafter in the United States, or which exist at all times in the West-India islands. Season and climate vary this, as well as all other diseases. Bark and wine, so fatal in this, may be proper in a future yellow fever. But in the climate of the United States, I believe it will seldom appear with such symptoms of prostration and weakness, as not to require, in its first stage, evacuations of some kind.
The only inquiry, when the disease makes its appearance, should be, from what part of the body these evacuations should be procured; the order which should be pursued in obtaining them; and the quantity of each of the matters to be discharged, which should be withdrawn at a time.
Thus far did I venture, from my theory of the disease, and from the authorities of Dr. Hillary and Dr. Mosely, to decide in favour of evacuations in the yellow fever; but Dr. Wade, and Mr. Chisholm again support me by their practice in the fevers of the East and West-Indies. They both gave strong mercurial purges, and bled in some cases. Dr. Wade confirmed, by his practice, the advantage of gradually abstracting stimulus from the system. He never drew blood, even in the most inflammatory cases, until he had first discharged the contents of the bowels. The doctor has further established the efficacy of a vegetable diet and of water as a drink, as the best means of preventing the disease in a hot climate.
The manner in which the miasmata that produce the plague act upon the system is so much like that which has been described in the yellow fever, and the accounts of the efficacy of low diet, in preparing the body for its reception, and of copious bleeding, cold air, and cold water, in curing it, are so similar, that all the directions which relate to preventing, mitigating, or curing the yellow fever may be applied to it. The fluids in the plague show a greater tendency to the skin, than they do in the yellow fever. Perhaps, upon this account, the early use of powerful sudorifics may be more proper in the former than in the latter disease. From the influence of early purging and bleeding in promoting sweats in the yellow fever, there can be little doubt but the efforts of nature to unload the system in the plague, through the channel of the pores, might be accelerated by the early use of the same remedies. One thing, with respect to the plague, is certain, that its cure depends upon the abstraction of stimulus, either by means of plentiful sweats, or of purulent matter from external sores. Perhaps the efficacy of these remedies depends wholly upon their elevating the system from its prostrated state in a gradual manner. If this be the case, those natural discharges might be easily and effectually imitated by small and repeated bleedings.
To correspond in quantity with the discharge from the skin, blood-letting in the plague, when indicated, should be copious. A profuse sweat, continued for twenty-four hours, cannot fail of wasting many pounds of the fluids of the body. This was the duration of the critical sweats in the famous plague which was known by the name of the English sweating sickness, and which made its appearance in the army of Henry VII. in Milford-Haven in Wales, and spread from thence through every part of the kingdom.
The principles which lead to the prevention and cure of the yellow fever and the plague, apply with equal force to the mitigation of the measles, and to the prevention or mitigation of the scarlatina anginosa, the dysentery, and the inflammatory jail fever. I have remarked elsewhere[98], that a previous vegetable diet lessened the violence and danger of the measles. Dr. Sims taught me, many years ago, to prevent or mitigate the scarlatina anginosa, by means of gentle purges, after children are infected by it[99]. Purges of salts have in many instances preserved whole families and neighbourhoods from the dysentery, where they have been exposed to its remote cause. During the late American war, an emetic seldom failed of preventing an attack of the hospital fever, when given in its forming state[100]. I have had no experience of the effects of previous evacuations in abating the violence, or preventing the mortality of the malignant sore throat, but I can have no doubt of their efficacy, from the sameness of the state of the system in that disease, as in other malignant fevers. The debility induced in it is from depression, and the supposed symptoms of putrefaction are nothing but the disguised effects of a sudden and violent pressure of an inflammatory stimulus upon the arterial system.
With these observations I close the history of the rise, progress, symptoms, and treatment of the bilious remitting yellow fever, which appeared in Philadelphia in the year 1793. My principal aim has been to revive and apply to it the principles and practice of Dr. Sydenham, and, however coldly those principles and that practice may be received by some physicians of the present day, I am convinced that experience, in all ages and in all countries, will vouch for their truth and utility.