The letter of the college of physicians has served to confirm me in an opinion, that the plagues which occasionally desolated most of the countries of Europe, in former centuries, and which were always said to be of foreign extraction, were of domestic origin. Between the years 1006 and 1680, the plague was epidemic fifty-two times all over Europe. It prevailed fourteen times in the 14th century. The state of Europe, in this long period, is well known. Idleness, a deficiency of vegetable aliment, a camp life, from the frequency of wars, famine, an uncultivated and marshy soil, small cabins, and the want of cleanliness in dress, diet, and furniture, all concurred to generate pestilential diseases. The plagues which prevailed in London, every year from 1593 to 1611, and from 1636 to 1649, I believe were generated in that city. The diminution of plagues in Europe, more especially in London, appears to have been produced by the great change in the diet and manners of the people; also by the more commodious and airy forms of the houses of the poor, among whom the plague _always_ makes its first appearance. It is true, these plagues were said by authors to have been imported, either directly or indirectly, from the Levant; but the proofs of such importation were as vague and deficient as they were of the West-India origin of our epidemic. The pestilential fevers which have been mentioned, have been described by authors by the generic name of the plague, but they appear to have originated from putrid vegetable exhalations, and to have resembled, in most of their symptoms, the West-India and _North-American_ yellow fever. I shall resume this interesting subject in another place, in which I shall mention a number of additional facts, not only in support of the domestic origin of the bilious yellow fever, but of its not spreading by contagion, and of course of its being impossible to import it. I shall at the same time enumerate all its different sources, and point out the means of destroying or removing them, and thus of exterminating the disease from our country. With these observations I conclude the history of the epidemic fever of the year 1793. A few of its symptoms, which have been omitted in this history, will be included in the method of cure, for they were discovered or produced by the remedies which were given for that purpose. [Hand] The following page begins an account of the states of the thermometer and weather, from the 1st of January to the 1st of August, and of the states of the barometer, thermometer, winds, and weather, from the 1st of August to the 9th of November, 1793. The times of observation, for the first three months are at 7 in the morning, and 2 in the afternoon; for the next five months they are at 6 in the morning, and 3 in the afternoon. From the 1st of October to the 9th of November, they are as in the first three months.