The mortality of this fever was considerable, where those distressing circumstances took place. In more favourable circumstances, it yielded to early depletion, and afterwards to the bark. Relapses were frequent, from premature exposure to the air. Those only escaped them who had been salivated, by accident or design, for the cure of the fever.
This disease was observed very generally to prevail most in high situations, which had been for years distinguished for their healthiness, while the low grounds, and the banks of creeks and rivers, were but little affected by it. The unusual quantity of rain, which had fallen during the summer months, had produced moisture in the former places, which favoured putrefaction and exhalation, while both were prevented, in the latter places, by the grounds being completely covered with water.
For a history of the uncommonly cold and tempestuous winter of 1804 and 1805, the reader is referred to the Account of the Climate of Pennsylvania, in the first volume of these Inquiries and Observations.
During the months of January, February, and March, there were a number of bilious catarrhs and pleurisies.
On the 7th of April, I visited a patient in the yellow fever with Dr. Stewart. He was cured, chiefly by copious bleeding.
The weather was rainy in May. After the middle of June, and during the whole month of July, there fell no rain. The mercury in Fahrenheit fluctuated, for ten days, between 90° and 94°, during this month. The diseases which occurred in it were cholera infantum, dysenteries, a few common bilious, and eight cases of yellow fever. Three of the last were in Twelfth, between Locust and Walnut-streets, and were first visited, on the 14th and 15th of the month, by Dr. Hartshorn, as out-patients of the Pennsylvania hospital. Two of them were attended, about a week afterwards, by Dr. Church, in Southwark, and the remaining three by Dr. Rouisseau and Dr. Stewart, in the south end of the city.
On the third of August, there fell a heavy shower of rain, but the weather, during the remaining part of the month, was warm and dry. The pastures were burnt up, and there was a great deficiency of summer vegetables in the neighbourhood of Philadelphia. The water in the Schuylkill was lower by three inches than it had been in the memory of a man of 70 years of age, who had lived constantly within sight of it.