The physiological action of this drug is not fully determined, yet it is quite probable that its chief action is upon the nervous system, affecting most prominently those portions of the spinal cord which receive and transmit reflex impulses, causing diminished reflex excitability of the nerve centers. It next acts upon the peripheral ends of the efferent nerves, causing paralysis, and finally affects the cerebrum, causing dilated pupils, intoxication, weakness of mind, hallucinations, etc. The heart is directly paralyzed under its influence, while through spasms of the vaso-motor system it causes contraction of the blood vessels, followed by dilatation. It thus causes primarily a depressed circulation in the cranium and throughout the body, lessening the blood supply, and thus causing, in connection with the action upon the nervous system, functional paralysis of nearly all the organs and tissues of the body. The subsequent dilatation gives rise secondarily to congestion, exciting the depressed nerve centers to a morbidly increased action, both sensory and motor, giving rise to hyperaesthesia and convulsions, thus, according to Dr. Hale , becoming " homoeopathic to all the morbid conditions and symptoms in which it has been found useful by the allopathic school ." Upon the skin the action is quite characteristic. Aside from the peripheral anaesthesia before mentioned, it causes acne-like eruptions, especially upon the face, neck, and shoulders, small boils, papules, pustules, and corroding ulcers. Characteristic symptoms.