The subarachnoid injection of cocaine derivatives for surgical analgesia has become an accepted and frequent procedure except in cases of severe myocardial degeneration, hypertension or psychoneurosis. The spinal anesthetic is easily administered; it eliminates the restlessness and excitement of the preanesthetic stage of ether, and it produces a greater degree of muscular relaxation. Moreover, spinal anesthesia has been repeated within short periods of time in the same individual without ill effects. Thus, Sullivan1records an instance in which five spinal anesthetics were given within thirty-eight hours. A priori one might hesitate to bathe the spinal cord and roots in a fluid that has been demonstrated experimentally to have toxic effects on neural tissue. In 1908 Spielmeyer2injected stovaine (amylocaine hydrochloride B. P.) into the subarachnoid spaces of dogs and apes and later found degeneration of the roots and the peripheral portion of the cord and retrograde changes in