The weather on the 19th, 20th, 21st, and 22d days of July was very warm, the mercury being at 90° in Fahrenheit's thermometer. The fevers of this month were all accompanied with black discharges from the bowels. Mr. Kittera, one of the representatives of Pennsylvania in the congress of the United States, in consequence of great fatigue on a warm day, was affected with the usual symptoms of the yellow fever. During his illness he constantly complained of more pain in the left, than in the right side of his head. His pulse was more tense in his left, than in his right arm. During his convalescence, it was more quick in the left arm, than it was in the right. He was cured by a salivation and the loss of above 100 ounces of blood. His head-ach was relieved by the application of a bladder half filled with ice to his forehead. Most of the cases of bilious fever, which came under my notice, were attended with quotidian, tertian, or quartan intermissions. In a few of my patients there was a universal rash. Dr. Woodhouse informed me, that he had seen several instances in which the yellow fever appeared in the same place in which some soldiers had laboured under the dysentery. These facts show the unity of fever, and the impracticability of a nosological arrangement of diseases. The cholera infantum was severe and fatal, in many instances, during this month. It yielded to blood-letting in a child of Mr. Conyngham, which was but four months old. In a child of seven weeks old which came under my care, I observed the coldness, chills, hot fits, and remissions of the bilious fever to be as distinctly marked as ever I had seen them in adult patients. In a child of Mr. Darrach, aged 5 months, the discharges from the bowels were of a black colour. I mention these facts in support of an opinion I formerly published, that the cholera infantum is a bilious fever, and that it rises and falls in its violence with the bilious fever of grown persons. About the latter end of this month and the beginning of August, there were heavy showers of rain, which carried away fences, bridges, barns, mills, and dwelling-houses in many places. Several cases of bilious yellow fever occurred in the month of August. In one of them it was accompanied with that morbid affection in the wind-pipe which has been called cynanche trachealis. It was remarkable that sweating became a more frequent symptom of the fevers of this month than it had been in July. Hippocrates ascribes this change in the character of bilious fevers to rainy weather. Perhaps it was induced by the rain which fell in the beginning of the month, in the fevers which have been named.