+History.+ From Corning we learn that the ancient Assyrians alleviated and even entirely prevented the pain incident to circumcision by compressing the veins in the neck. Unconsciousness was probably induced in this way together with pressure on the carotids. In India, centuries ago, the effects of opium and of Indian hemp were known and employed, and the ancient Egyptians were also conversant with the soporific effects of many drugs. We learn, from the same authority, much which he gathered from literature about the history of local anesthesia, and it is from Corning’s well-known book on local anesthesia that most of this history is quoted. In Peru, the Spanish conquerors learned that the coca loaf was held in high esteem by the natives, inasmuch as they observed that it was chewed by the high priests and nobility only, the vulgar being denied this privilege except as a reward of great merit or of distinguished valor. The leaf was regarded with awe and superstition and was supposed to possess supernatural powers. After the fall of the Incas, the Spanish not only permitted but encouraged the general use of the leaf in order to obtain more work from the natives, a result which the drug seemed to effect. It was also a source of great revenue to them and was sold at exorbitant profit to the natives who became enslaved to its effects but were able to endure great hardship while under its influence. Chemists throughout the world, recognizing the potent action of the coca leaf, were soon engaged in the effort of extracting its active principle. In 1859, after many had tried and failed, cocaine was evolved from crude extractives. Authorities differ as to whether it was Mann or Neimann, a pupil of Woehler, who first presented cocaine to the chemical world; however, fifteen added years elapsed before practical use for it was found. In 1862, Professor Schraff discovered that the tip of the tongue was rendered numb, and insensible when a little of the cocaine alkaloid was applied to it and that it remained so for a considerable length of time. Significant though this experiment was, the action of cocaine on the nerve-filaments was not recognized and the matter was not followed up until Dr. Karl Koller, of Vienna, began his experiments which resulted in a universal awakening to the use of a substance which, though known, had been allowed to remain unnoticed for ages. Its anesthetic effect upon the eye was demonstrated by Koller at the Opthalmologic Congress at Heidelberg in 1884. Dr. H. D. Noyes was first to direct the attention of the American practitioners to Koller’s results in the use of the drug. Its introduction was one of the greatest triumphs of modern surgery. It makes possible the discard of the systemic anesthetics in all minor surgical operations and also in many operations of considerable magnitude. In the laboratory of Professor Stricker, Koller experimented on the eyes of a number of animals and thus reports his findings: