CASE V.--A gentleman, aged thirty-nine, unmarried, of correct habits, and good general health, consulted me on the 19th of April, 1865, in reference to a peculiar nervous affection with which he had suffered for several months. He stated to me that, being engaged upon a literary labor of some importance, he had given the greater part of his time to the studies necessary to its being carried on with success, and was conscious of having overtasked his mental powers. So great, however, was his ambition to excel in his undertaking, that he had persevered notwithstanding the admonitions of friends, and the still more pointed warnings he had received from his own sensations. Instead of sleeping, as had been his custom, from seven to eight hours, he rarely, for nearly a year, had slept more than four hours out of the twenty-four, and frequently even less than this. He did not, however, feel the want of sleep. In fact he was never sleepy, and if this had been the only ill consequence of his severe application I should probably not have had him under my charge at all, so little weight did he attach to the condition which it was of the first importance should be relieved. The symptom of disordered action which attracted his attention most was an inability to concentrate his mind upon subjects about which he wished to write. There was no difficulty in maintaining a connected line of reasoning, except when he attempted to put his ideas on paper, and then he found it utterly impossible to direct his thoughts in a methodical way. He conversed with me very intelligently in reference to his case, and was perfectly conscious of the difficulty under which he labored. As an instance of the character of his disease, he said that the day before he came to see me he had reflected to his entire satisfaction upon certain points in literature which he was investigating, and that when he came to read over what he had written he found it was a tissue of the most arrant nonsense. The subject of his thoughts was the Greek drama, and the ideas in reference to it, which he communicated to me, were in the highest degree logical and interesting. He then showed me the first page of what he had written, and though he was annoyed at the nonsensical strains of his language, he could not at the same time conceal his amusement at its utter absurdity. I quote a few lines from this paper.