W. C. a man aged sixty-three, was admitted into the hospital January 21, 1797. The persons, who attended at his admission, deposed, that he had been disordered five months; that he never had been insane before, and that the disease came on shortly after the death of his son. He was in a very anxious and miserable state. No persuasion could induce him to take nourishment; and it was with extreme difficulty that any food could be forced upon him. He paced about with an hurried step; was often suddenly struck with the idea of having important business to adjust in some distant place, and which would not admit of a moment's delay. Presently after, he would conceive his house to be on fire, and would hastily endeavour to rescue his property from the flames. Then he would fancy that his son was drowning, that he had twice sunk: he was prepared to plunge into the river to save him, as he floated for the last time: every moment appeared an hour until he rose. In this miserable state he continued till the 27th, when, with great perturbation, he suddenly ran into his room, threw himself on the bed, and in a few minutes expired. The head was opened twenty-four hours after death. The pericranium was but slightly adherent to the scull: the tunica arachnoidea, particularly where the hemispheres meet, was of a milky whiteness. Between this membrane, which was somewhat thickened, and the pia mater, there was a very large collection of water: the pia mater was inflamed: the veins of this membrane were enlarged beyond what I had ever before observed: there was a striking appearance of air in the veins: the medullary substance of the brain, when cut into, bled freely, and seemed spungy from the number and enlargement of its vessels: in the ventricles, which were of a natural capacity, there was about half an ounce of water: the brain was of a healthy consistence. CASE XX.