The reader will perceive, from these facts and reasonings, that I have relinquished the opinion published in my account of the yellow fever in the years 1793, 1794, and 1797, respecting its contagious nature. I was misled by Dr. Lining, and several West-India writers, in ascribing a much greater extent to the excreted matters in producing the disease, than I have since discovered to be correct, and by Bianchi, Lind, Clark, and Cleghorn, in admitting even the common bilious fever to be contagious. The reader will perceive, likewise, that I have changed my opinion respecting one of the modes in which the plague is propagated. I once believed, upon the authorities of travellers, physicians, and schools of medicine, that it was a highly contagious disease. I am now satisfied this is not the case; but, from the greater number of people who are depressed and debilitated by poverty and famine, and who live in small and filthy huts[47] in the cities of the east, than in the cities of the United States, I still believe it to be more frequently communicated from an intercourse with sick people by the morbid excretions of the body, than the yellow fever is in our country. For the change of my opinion upon this subject, I am indebted to Dr. Caldwell's and Mr. Webster's publications upon pestilential diseases, and to the travels of Mariti and Sonnini into Syria and Egypt. I reject, of course, with the contagious quality of the plague, the idea of its ever being imported into any country so as to become epidemic, by means of a knife-case, a piece of cotton, or a bale of silks, with the same decision that I do all the improbable and contradictory reports of an epidemic yellow fever being imported in a sailor's jacket, or in the timbers and sails of a ship that had been washed by the salt water, and fanned by the pure air of the ocean, for several weeks, on her passage from the West-Indies to the United States. [47] M. Savary, in his Travels, says, two hundred persons live in Cairo within a compass that accommodates but thirty persons in Paris.