The susceptibility of rats to electric shock

Exps. on 87 rats of both sexes, varying in weights and ages from 90 to 230 days, followed preliminary tests on a number of other rats. 60 cycle alternating current of 49 [plus or minus] 0.1 milliamperes at approx. 8000 volte was applied through electrodes applied with kaolin and zinc sulphate paste to face and base of tail. From the small number of rats shocked in each of several ways, the following suggestions are derived: (1) 45 sec. of continuing current of amperage specified is not uniformly fatal; 1 min. may be. (2) With regularly spaced intermittent application of brief durations, slightly greater inclusive times of application are required, but the time of total current flow is a fraction of the lethal time for continuous flow. (3) Sex and physiological condition probably are important factors in determining survival, but weight in itself probably is not. A bearing of the results on McDougall''s "Lamarckian Experiment" is suggested.