The convalescence from this fever was in general rapid, but in some cases it was very slow. I was more than usually struck by the great resemblance which the system in the convalescence from this fever bore to the state of the body and mind in old age. It appeared, 1. In the great weakness of the body, more especially of the limbs. 2. In uncommon depression of mind, and in a great aptitude to shed tears. 3. In the absence or short continuance of sleep. 4. In the frequent occurrence of appetite, and, in some cases, in its inordinate degrees. And 5. In the loss of the hair of the head, or in its being suddenly changed in some cases to a grey colour.
Pure air, gentle exercise, and agreeable society removed the debility both of body and mind of this premature and temporary old age. I met with a few cases, in which the yellow colour continued for several weeks after the patient's recovery from all the other symptoms of the fever. It was removed most speedily and effectually by two or three moderate doses of calomel and rhubarb.
A feeble and irregular intermittent was very troublesome in some people, after an acute attack of the fever. It yielded gradually to camomile or snake-root tea, and country air.
In a publication, dated the 16th of September, I recommended a diet of milk and vegetables, and cooling purges to be taken once or twice a week, to the citizens of Philadelphia. This advice was the result of the theory of the disease I had adopted, and of the successful practice which had arisen from it. In my intercourse with my fellow-citizens, I advised this regimen to be regulated by the degrees of fatigue and foul air to which they were exposed. I likewise advised moderate blood-letting to all such persons as were of a plethoric habit. To men whose minds were influenced by the publications in favour of bark and wine, and who were unable at that time to grasp the extent and force of the remote cause of this terrible fever, the idea of dieting, purging, or bleeding the inhabitants of a whole village or city appeared to be extravagant and absurd: but I had not only the analogy of the regimen made use of to prepare the body for the small-pox, but many precedents in favour of the advice. Dr. Haller has given extracts from the histories of two plagues, in which the action of the miasmata was prevented or mitigated by bleeding[89]. Dr. Hodges confirms the utility of the same practice. The benefits of low diet, as a preventive of the plague, were established by many authors, long before they received the testimony of the benevolent Mr. Howard in their favour. Socrates in Athens, and Justinian in Constantinople, were preserved, by means of their abstemious modes of living, from the plagues which occasionally ravaged those cities. By means of the low diet, gentle physic, and occasional bleedings, which I thus publicly recommended, the disease was prevented in many instances, or rendered mild where it was taken. But my efforts to prevent the disease in my fellow-citizens did not end here. I advised them, not only in the public papers, but in my intercourse with them, to avoid heat, cold, labour, and every thing else that could excite the miasmata (which I knew to be present in all their bodies) into action. I forgot, upon this occasion, the usual laws which regulate the intercourse of man with man in the streets, and upon the public roads, in my excursions into the neighbourhood of the city. I cautioned many persons, whom I saw walking or riding in an unsafe manner, of the danger to which they exposed themselves; and thereby, I hope, prevented an attack of the disease in many people.
It was from a conviction of the utility of low diet, gentle evacuations, and of carefully shunning all the exciting causes which I have mentioned, that I concealed, in no instance, from my patients the name of their disease. This plainness, which was blamed by weak people, produced strict obedience to my directions, and thereby restrained the progress of the fever in many families, or rendered it, when taken, as mild as inoculation does the small-pox. The opposite conduct of several physicians, by preventing the above precautions, increased the mortality of the disease, and, in some instances, contributed to the extinction of whole families.
I proceed now to make a few remarks upon the remedies recommended by Doctors Kuhn and Stevens, and by the French physicians. The former were bark, wine, laudanum, spices, the elixir of vitriol, and the cold bath.
In every case in which I prescribed bark, it was offensive to the stomach. In several tertians which attended the convalescence from a common attack of the fever, I found it always unsuccessful, and once hurtful. Mr. Willing took it for several weeks without effect. About half a pint of a weak decoction of the bark produced, in Mr. Samuel Meredith, a paroxysm of the fever, so violent as to require the loss of ten ounces of blood to moderate it. Dr. Annan informed me that he was forced to bleed one of his patients twice, after having given him a small quantity of bark, to hasten his convalescence.
It was not in this epidemic only that the bark was hurtful. Baron Humboldt informed me, that Dr. Comoto had assured him, it hastened death in every case in which it was given in the yellow fever of Vera Cruz. If, in any instance, it was inoffensive, or did service, in our fever, I suspect it must have acted upon the bowels as a purge. Dr. Sydenham says the bark cured intermittents by this evacuation[90]; and Mr. Bruce says it operated in the same way, when it cured the bilious fevers at Massuah.