Studies on the efficacy of the various methods of artificial respiration abound in the literature. However, a comparative study of a number of current methods by the same group of observers, using a significant number of nonrigid human corpses, is not available. CHOICE OF SUBJECTS Four types of subjects have been used for the study of the efficiency of various methods of artificial respiration: (a) human corpses prior to the occurrence of rigor mortis, (b) normal passive human subjects with "voluntarily suspended respirations," (c) deeply anesthetized and/or curarized animals, (d) human subjects deeply anesthetized or curarized, or apneic for some other reason. There have been investigations in which one or more of these methods have been used.1However, the results of different investigators and methods vary widely; the authors fail to consider all currently advocated manual and mechanical methods and usually report only a few cases. Laboratory animals were