_Digitalis_ is only indirectly useful as an hypnotic. In cases of cardiac disease, with enfeeblement of the heart, dyspnoea, dropsy, and sleeplessness, digitalis is often of the greatest service. It has also been highly recommended in delirium tremens. Administered in the form of an infusion, it has been given in doses of a tablespoonful, every four hours, with apparently good effect. Its use is indicated in cases characterized by weakness of the heart, with a rapid and feeble pulse. Under its influence the state of the circulation improves, delirium ceases, and sleep occurs. _Camphor._--This substance is not an hypnotic, but it forms a valuable addition to various hypnotic compounds. It is a cerebral stimulant, and aids in the establishment of that nervous tranquility which favors the incidence of sleep. It may, therefore, be advantageously associated with opiates in the restlessness and insomnia of exhaustion. Tully’s Powder, a valuable substitute for Dover’s Powder, contains camphor. This renders it preferable to the ordinary opiates in typhoid fever, and in other exhausting diseases. _Musk_, the dried secretion of the preputial follicles of the musk-deer, is a substance which, on account of its high price, is rarely used as an hypnotic. Given in doses of ten grains, every two or three hours, it is exceedingly valuable (Stillé and Maisch) for the relief of “all those nervous phenomena which are represented by the term _ataxia_, and among them subsultus tendinum, mild muttering delirium, floccitation, muscæ volitantes, and hiccough, with a small, frequent, tremulous or irregular pulse, without coma and without collapse. Under these circumstances musk tends to produce refreshing sleep, while it calms muscular spasm and favors perspiration, while the pulse grows fuller, more regular, and less frequent.... In proportion as ataxic prevail over adynamic phenomena is musk advantageous.” Such conditions are chiefly encountered in typhus, typhoid fever, the eruptive fevers, and pneumonia. Musk is very efficacious for the relief of “wakefulness resulting from combined mental and bodily fatigue--such cases, in fact, as are benefitted by valerian, camphor, asafetida, and ammonia.” _Valerian_ and its different preparations form a typical class of agents which indirectly favor sleep by their gently stimulant effect upon the brain. They are all useful in quieting that form of hysterical excitement to which women are liable during the “change of life.” That form of restlessness, usually resulting from fatigue, in which the patient feels as if she cannot sit still, is often relieved very promptly by the valerianate of ammonia. Wakefulness caused by neuralgic pains, or by exhaustion, often yields readily to scruple doses of valerianate of zinc or ammonia. The elixir of the valerianate of ammonia is a very elegant preparation of the drug.