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

M. Matteucci not only corroborated from his researches the " current proper in frogs," noticed by Nobili,but also discovered and demonstrated in man, and all warm-blooded animals, the existence of a natural muscular electric current. By cutting the muscles of a living animal, and thus introducing into the wound the nerve of the fresh prepared frog--galvanoscope, so that the end of the nerve touched the very bottom of the wound, whilst another point of the same nerve touched only the edges of the wound, he obtained a decided contraction. This, he says, was fair proof of the existence of a natural electric cur- rent, directed in the muscles from the deep interior of their body to the surface. This experiment we have often seen succeed, if only nicely conducted, whatever be the kind of muscle, or whatever be the animal whose live muscle is so touched, even where the muscle of a warm-blooded animal has been separated from the live animal for some time. But to magnify the effects produced by the native electric current of animals, M. Matteucci increased the intensity of the animal electric current, by uniting- a series of separate muscles, much as we form a voltaic pile. Thus having prepared, by cutting smoothly a number of half thighs of frogs, he arranged them in regular order, so that in each point of contact of half thigh to half thigh, exactly in the same order of direction, it is, on the one hand, terminated by the interior of the muscles, and on the other, it is terminated by the exterior or surface of the thigh. Then these two extreme ends are placed in communica- tion with distilled water, into which arc now plunged the termi- nal platinum ribbons of a sensitive galvanometer ; i. c., after being quite certain that they do not transmit any other current before the flesh is included in the circuit (as a battery) to be tested. Immediately there is obtained the evidence of a mus- cular electric current, and that always directed from the inter- nal to the surface of the muscles, — the intensity of which varies according to the number of half thighs of frogs that compose the given pile ; as, for instance, 3° to 4° are observed, indicated by the needle from two thighs, 6° to 8° from four, 10° to 12° from six half thighs, and so on.