arachnoidea and pia mater; the latter membrane was much suffused with blood, and many of its vessels were considerably enlarged: the lateral ventricles contained at least six ounces of water: the brain was very firm. CASE XV. J. A. a man forty-two years of age, was first admitted into the house on June 27, 1795. His disease came on suddenly whilst he was working in a garden, on a very hot day, without any covering to his head. He had some years before travelled with a gentleman over a great part of Europe: his ideas ran particularly on what he had seen abroad; sometimes he conceived himself the king of Denmark, at other times the king of France. Although naturally dull and wanting common education, he professed himself a master of all the dead and living languages; but his most intimate acquaintance was with the old French; and he was persuaded he had some faint recollection of coming over to this country with William the Conqueror. His temper was very irritable, and he was disposed to quarrel with every body about him. After he had continued ten months in the hospital, he became tranquil, relinquished his absurdities, and was discharged well in June 1796. He went into the country with his wife to settle some domestic affairs, and in about six weeks afterwards relapsed. He was readmitted into the hospital August 13th. He now evidently had a paralytic affection, his speech was inarticulate, and his mouth drawn aside. He shortly became stupid, his legs swelled and afterwards ulcerated; at length his appetite failed him; he became emaciated, and died December 27th, of the same year. The head was opened twenty hours after death. There was a greater quantity of water between the different membranes of the brain than has ever occurred to me. The tunica arachnoidea was generally opake and very much thickened: the pia mater was loaded with blood, and the veins of that membrane were particularly enlarged. On the fore-part of the right hemisphere of the brain, when stripped of its membranes, there was a blotch, of a brown colour, several shades darker than the rest of the cortical substance: the ventricles were much enlarged, and contained, by estimation, at least six ounces of water. The veins in these cavities were particularly turgid. The consistence of the brain was firmer than usual. CASE XVI.