_Insomnia in syphilis._--In advanced stages of syphilitic cachexia, a variety of wakefulness independent of pain is sometimes observed. It is marked by a tendency to wake at a fixed hour of the night, frequently about two o’clock in the morning, after which time sleep is impossible. The symptoms of constitutional disease are not prominent in these cases, but the history and the evident cachexia make their nature apparent. They usually yield to a mercurial treatment. In their comparative freedom from severe pain, such patients present a striking contrast to certain cases of syphilitic rheumatism, or neuralgia. The nocturnal suffering in such instances is frightful. It can be finally overcome by anti-syphilitic treatment; but, while waiting for the radical cure, palliatives are needed. Chlorodyne and similar combinations of all the anodyne drugs afford the most effectual means of relief. I have sometimes found it necessary to increase the dose until the characteristic delirium produced by solanaceous drugs was manifested. The relief thus procured sometimes continues for many days after the cessation of hypnotic medication. _Insomnia in various disorders of nutrition._--The wakefulness experienced by syphilitic patients is not peculiar to their cachexia. It is a result of blood disorder and impoverishment that is common among the victims of rheumatism, lithæmia, syphilis, malarial poisoning, cancerous dyscrasia, chronic toxæmia of every form, and ordinary anæmia. Imperfect blood supply deteriorates the nutrition of the brain, and renders it so excitable that sleep is interrupted so soon as the period of profound repose is past. This occupies about four hours (see p. 16), hence the patient who falls asleep at ten o’clock is ready to wake up at two in the morning, and only sleeps again, if at all, when wearied with tossing till daylight. Such patients often derive great benefit from a morning nap thus obtained between the hours of five and seven.