I used bleeding in several cases on the second, third, and fourth days of the disease, where it had appeared to be improper in its first stage. The cases which required bleeding were far from being general. I saw two instances of syncope of an alarming nature, after the loss of ten ounces of blood; and I heard of one instance of a boy who died in half an hour after this evacuation. I remarked that purges of all kinds worked more violently than usual in this disease. The convalescence from it was very slow, and a general languor appeared to pervade the citizens for several weeks after it left the city. The month of December, 1790, was extremely and uniformly cold. In the beginning of the month of January, 1791, the weather moderated, and continued to be pleasant till the 17th, on which day the navigation of the Delaware, which had been completely obstructed by the ice, was opened so as to admit of the arrival of several vessels. During the month of December many people complained of _colds_; but they were ascribed wholly to the weather. In January four or five persons in a family were affected by colds at the same time; which created a suspicion of a return of the influenza. This suspicion was soon confirmed by accounts of its prevailing in the neighbouring counties of Chester and Montgomery, in Pennsylvania, and in the distant states of Virginia and Rhode-Island. It did not affect near so generally as in the two former times of appearance. There was no difference in the method of treating it. While the common inflammatory diseases of the winter bore the lancet as usual, it was remarked that patients who were attacked by the influenza, did not bear bleeding in a greater proportion, or in a larger quantity, than in the two former times of its appearance in the city. I shall conclude this account of the influenza by the following observations: 1. It exists independently of the sensible qualities of the air, and in all kinds of weather. Dr. Patrick Russel has proved the plague to be equally independent of the influence of the sensible qualities of the atmosphere, to a certain degree. 2. The influenza passes with the utmost rapidity through a country, and affects the greatest number of people, in a given time, of any disease in the world. 3. It appears from the histories of it which are upon record, that neither climate, nor the different states of society, have produced any _material_ change in the disease. This will appear from comparing the account I have given, with the histories of it which have lately been given by Dr. Grey, Dr. Hamilton, Dr. A. Fothergill, Mr. Chisholm, and other modern physicians. It appears further, that even time itself has not been able materially to change the type of this disease. This is evident, from comparing modern accounts of it with those which have been handed down to us by ancient physicians.