Abstract
Direct current electric shocks were applied along the forelimb to forelimb pathway in rabbits. The effects on respiration were found to depend on the current value, which from this point of view can be divided into four ranges. Range I, in which there was no effect on respiration, included currents up to 50 mA. In range II (currents from 50 mA to 180 mA) there was arrest of respiration during the early part of the shock. In range III the current was from 180 mA to 350 mA, and respiration was arrested throughout the shock with spontaneous resumption immediately afterwards. In range IV the current was from 350 mA upwards (the highest current in this series was 1·8 A) and resulted in arrest of respiration throughout the shock followed by a delay before spontaneous resumption of respiration. A number of animals in range IV died without breathing again after the end of the shock. In these cases death could be explained by ventricular fibrillation, by asphyxia resulting from the long duration of the shock, or by the fact that the shocks were the last of a series at high currents producing marked damage.