Acute intoxication in man from the use of the local anesthetics is far more common than is indicated by the number of recorded cases. We undertook to investigate the causes of such intoxication, and sought to find means of avoiding it, or combating it when it arises. This investigation has included a study of the literature of the more important cases of human intoxication, and the performance of over 300 experiments on cats. The details of this work are published elsewhere,1 the present communication being limited to a short discussion of the more important facts brought to light, especially with reference to their bearing on the clinical problem.
Nine of the local anesthetics were studied, and the maximum toxicity of each was determined by rapid intravenous injection into cats. The drugs used, the fatal dose of each, the concentrations of the solutions employed, and the relative toxicities of the