V. Inhibition of the mammalian heart

The following conclusions are based upon a long series of experiments performed upon the cat, dog, rabbit, rat, hedgehog, and guinea-pig, the cat being the animal commonly used. The animals were anesthetized, usually with chloroform; artificial respiration was kept up ; the thorax and often the pericardial sac were laid open, and the action of the heart was examined with the aid of the graphic method.