I suppose the inflammation, in most cases, to precede the effusion of water. I have met with only one case in which the slow and tense pulse was absent; and out of six dissections of patients whom I have lost by this disease, the brains of four of them exhibited marks of inflammation. Mr. Davis discovered signs of inflammation, after death from this disease, to be universal. In eighteen or twenty dissections, he tells us, he found the pia mater always distended with blood[55]. Where signs of inflammation have not occurred, the blood-vessels had probably relieved themselves by the effusion of serum, or the morbid action of the blood-vessels had exceeded that grade of excitement, in which only inflammation can take place. I have seen one case of death from this disease, in which there was not more than a tea-spoonful of water in the ventricles of the brain. Dr. Quin mentions a similar case. Here death was induced by simple excess of excitement. The water which is found in the ventricles of the brain refuses to coagulate by heat, and is always pale in those diseases, in which the serum of the blood, in every other part of the body, is of a yellow colour. [55] Medical Journal, vol. VIII. In addition to these facts, in support of the internal dropsy of the brain being the effect of inflammation, I shall mention one more, communicated to me in a letter, dated July 17th, 1795, by my former pupil, Dr. Coxe, while he was prosecuting his studies in London. "It so happened (says my ingenious correspondent), that at the time of my receiving your letter, Dr. Clark was at the hospital. I read to him that part which relates to your success in the treatment of hydrocephalus internus. He was much pleased with it, and mentioned to me a fact which strongly corroborates your idea of its being a primary inflammation of the brain. This fact was, that upon opening, not long since, the head of a child that had died of this disease, he found between three and four ounces of water in the ventricles of the brain; also an inflammatory crust on the optic nerves, as thick as he had ever observed it on the intestines in a state of inflammation. The child lost its sight before it died. The crust accounted in a satisfactory manner for its blindness. Perhaps something similar may always be noticed in the dissections of such as die of this disease, in whom the eyes are much affected." Having adopted the theory of this disease, which I have delivered, I resolved upon such a change in my practice as should accord with it. The first remedy indicated by it was I. _Blood-letting._ I shall briefly mention the effects of this remedy in a few of the first cases in which I prescribed it. CASE I.