[22] Outlines of a theory of fever. [23] Essay on the Epidemic Disease of Lying-in Women, of the years 1787 and 1788, p. 34. I wish it to be remembered here, that the yellow fever, like all other diseases, is influenced by climate and season. The determination of the fluids is seldom the same in different years, and I am sure it varied with the weather in the disease which I am now describing. Dr. Jackson speaks of the head being most affected in the West-India fevers in _dry_ situations. Dr. Hillary says, that there was an unusual determination of the blood towards the brain, after a _hot_ and _dry_ season, in the fevers of Barbadoes in the year 1753; and Dr. Ferriar, in his account of an epidemic jail fever in Manchester, in 1789, 1790, informs us, that as soon as frost set in, a delirium became a more frequent symptom of that disease, than it had been in more temperate weather. III. The _stomach_ and _bowels_ were affected in many ways in this fever. The disease seldom appeared without nausea or vomiting. In some cases, they both occurred for several days or a week before they were accompanied by any fever. Sometimes a pain, known by the name of gastrodynia, ushered in the disease. The stomach was so extremely irritable as to reject drinks of every kind. Sometimes green or yellow bile was rejected on the first day of the disease by vomiting; but I much oftener saw it continue for two days without discharging any thing from the stomach, but the drinks which were taken by the patient. If the fever in any case came on without vomiting, or if it had been checked by remedies that were ineffectual to remove it altogether, it generally appeared, or returned, on the 4th or 5th day of the disease. I dreaded this symptom on those days, for although it was not always the forerunner of death, yet it generally rendered the recovery more difficult and tedious. In some cases the vomiting was more or less constant from the beginning to the end of the disease, whether it terminated in life or death. The vomiting which came on about the 4th or 5th day, was accompanied with a burning pain in the region of the stomach. It produced great anxiety, and tossing of the body from one part of the bed to another. In some cases, this painful burning occurred before any vomiting had taken place. Drinks were now rejected from the stomach so suddenly, as often to be discharged over the hand that lifted them to the head of the patient. The contents of the stomach (to be mentioned hereafter) were sometimes thrown up with a convulsive motion, that propelled them in a stream to a great distance, and in some cases all over the clothes of the by-standers. Flatulency was an almost universal symptom, in every stage of this disease. It was very distressing in many cases. It occurred chiefly in the stomach.