Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

Bernard electrized the long and delicate ears of a rabbit, in one of which he had already cut the left sympathetic nerve; while the other, on the right side, was left intact. Now, when the left ear was electrized, a rapidly-increased heat was noticed ; but when the right ear was electrized, as rapid a diminution of heat was produced. He explains this thus: the elevation of tempera- ture on the side where the nerve had been cut results from the circumstance that, under the influence of the pain, the heart acts more vigorously upon the arteries of the ear, which are already relaxed in consequence of the section of the ganglionic filament; while on the right side, where the nerve has not been cut, the electricity causes an excitation of the sentient nerves, which im- pression is transmitted to the spinal cord, and then again by a reflex to the sympathetic; hence the vessels of the ear are con- stricted, and therefore the action of the heart cannot produce the same results as it does on the other side, where no reflex action from the spinal cord to the sympathetic ganglia is possible. Professor Weber discovered, in 1846, that where the inferior cervical ganglia of the sympathetic is electrized by an active in- duction current, the pulsations of the heart are greatly increased. The same phenomenon occurs, if the cardiac branches from this ganglia are subjected to the action of the current. But if the vagi are electrized the action of the heart is diminished. If the current be stronger, or longer used, the heart's action comes to a stand-still. Professor Pflueger discovered, in 1856, that the splanchnic nerves exercise a similar controlling influence over the peristaltic movements of the intestines, much, indeed, as the vagi do over the contractions of the heart.* He found that when the electric current is applied to the splanchnic nerves, which take their rise from the six lower dorsal ganglia of the sympathetic, then the vermicular movements of the small intestines are very soon sus- pended. From this he inferred that there is a peculiar set of nerves for the ■physiological action of diminishing, or even sus- pending, the various movements of the intestines, and he desig- nated them as the " inhibitory system" of nerves. But Mr. * TJber das Hemmungs-Nervensysten fur die peristaltischen Bewegungen der Ge- darme, Berlin, 1856.