I had no intention of letting him “go to work” on Monday, or for at least two weeks subsequently. I was of the opinion, however, that after that time he could resume his labors to a slight extent, and gradually extend them--not to the limit they formerly reached, but to that degree which, while they would add to his reputation as a man of learning, would not exhaust the organ which it was so essential for his objects to preserve in a condition of unimpaired vigor. The result has been all that either he or myself could have desired. CASE VI.--A youth of fifteen was brought to me by his father, on the 16th of August, to be treated for obstinate wakefulness, the consequence of severe mental exertion at school several weeks previously. He had not attended school since the last of June, but had scarcely slept more than an hour or two each night since that time, according to his own and his father’s statement. He was a healthy, well-grown lad, with a good appetite, and nothing unusual in his appearance beyond a slight look of weariness and anxiety in his face. During the day there were no hallucinations of any kind, and toward evening he invariably felt overpowered with sleep. As soon, however, as he lay down he heard voices repeating extracts from the lessons he had recently been learning, and his mind became occupied with imaginary scenes in which the gods and goddesses of mythology and the heroes and poets of antiquity played prominent parts, and the whole power of his attention was thus kept engaged with these and other scenes which were formed with astonishing rapidity. Toward morning he fell into an uneasy slumber, and awoke feeling more weary even than when he had gone to bed. Medicines, among which opium was the chief, had been employed without success. On the contrary, his condition was manifestly rendered worse through their influence. Laudanum, of which he had taken large quantities, always caused headache, without producing the least amelioration in his symptoms. Notwithstanding the palpable connection which existed between the wakefulness and his former intense mental application, he had been allowed to continue his studies, and when he came to me had a Latin grammar in his hand, which he had been diligently studying in the street railway car!