Narcotics should be carefully distinguished from anæsthetics. Their use is different, not in degree only, but in character and purpose. Their legitimate object is two-fold: primarily, in a limited number of cases, to relieve or mitigate pain temporarily or permanently incurable; but secondarily and principally to cure what to a large and constantly increasing class in every civilized country is among the severest trials attendant on sickness, over-work, or nervous excitement—that loss of sleep which is a terrible affliction in itself, and aggravates, much more than inexperience would suppose, every form of suffering with which it is connected. Nature mercifully intended that prolonged intolerable pain should of itself bring the relief of sleep or swooning; and primitive races like the Red Indian, living in the open air, with dull imagination and insensible nerves, still find such relief. The victims of Mohawk and Huron tortures have been known, during a brief intermission of agony, to sleep at the stake till fire was used to awaken them. But among the many drawbacks of civilized life must be counted the tendency of artificial conditions to defeat some of Nature’s most merciful provisions. The nerves of civilized men are too sensitive, the brains developed by hereditary culture and constant exercise are too restless, to obtain from sleep that relief in pain, especially prolonged pain, that nature apparently intended. Many of us, even in sleep, are keenly sensitive to suffering, at least to chronic as distinguished from acute pain, to dull protracted pangs like those of rheumatism, ear-ache, or tooth-ache. A little sharper pain, and sleep becomes impossible. The sufferer is not only deprived of the respite that slumber should afford, but insomnia itself enhances his sensibility, besides adding a new and terrible torment of its own. Artificial prevention of sleep was notoriously among the most cruel and the most certainly mortal of mediæval or barbaric tortures. The sensations of one who has not slept for several nights, beginning with a restless, unnatural, constantly increasing consciousness of the brain, its existence and its action, passing by degrees into an acute, unendurably distressing irritation of that organ—generally unconscious or insensible, probably because its habitual sensibility would be intolerable—are indescribable, unimaginable by those who have not felt them; and seem to be proportionate to the activity of the intellect, the susceptibility of nerve and vitality of temperament—the capacity for pain and pleasure. In a word, the finer the physical and nervous character, the more terrible the torment of sleeplessness. A little more and the patient is confronted with one of the most frightful forms of pain and terror, the consciousness of incipient insanity. But long before reaching this stage, sleeplessness exaggerates pain and weakens the power of endurance, quickens the sensibility of the nerves,