Perhaps this difference in the operation of those two medicines depended upon the bark acting with an astringent, as well as stimulating power, chiefly upon the blood-vessels, while the action of the opium was more simply stimulating, and diffused at the same time over all the systems of the body. I shall say in another place that I sometimes directed a few drops of laudanum to be given in that state of extreme debility which succeeds a paroxysm of fever, with evident advantage. _Nitre_, so useful in common inflammatory fevers, was in most cases so offensive to the stomach in this fever, that I was seldom able to give it. Where the stomach retained it I did not perceive it to do any service. _Antimonials_ were as ineffectual as nitre in abating the action of the sanguiferous system, and in producing a sweat. I should as soon expect to compose a storm by music, as to cure a yellow fever by such feeble remedies. Thus have I finished the history of the symptoms, origin, and cure of the yellow fever as it appeared in Philadelphia in 1794, and in the winter of 1795. The efficacy of the remedies which have been mentioned was established by almost universal success. Out of upwards of 200 patients to whom I was called on the first stage of the fever, between the 12th of June, 1794, and the 1st of April, 1795, I lost but four persons, in whom the unequivocal symptoms had occurred, which characterize the first grade of the disease. It will be useful, I hope, to relate the cases of the patients whom I lost, and to mention the causes of their deaths. The first of them was Mrs. Gavin. She objected to a fifth bleeding in the beginning of a paroxysm of her fever, and died from the want of it. Her death was ascribed to the frequency of her bleedings by the enemies of the depleting system. It was said that she had been bled ten times, owing to ten marks of a lancet having been discovered on her arms after death, five of which were occasioned by unsuccessful attempts to bleed her. She died with the usual symptoms of congestion in her brain. Mr. Marr, to whom I was called on the first day of his disease, died in a paroxysm of his fever which came on in the middle of the seventh night, after six bleedings. I had left him, the night before, nearly free of fever, and in good spirits. He might probably have been saved (humanly speaking) by one more bleeding in the exacerbation of what appeared to be the critical paroxysm of his fever.