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

it was not so clear an evidence of animal electricity, but which was in fact equally as true. It is said that Dr. Galvani, at that time Professor of Anat- omy at Bologna, had his attention first drawn to an accidental and strange phenomenon by one of the medical students, that ultimately led him to the discovery of galvanism. Some frogs had just been dressed for a soup for Madame Galvani, who was an invalid, and hung along suspended by copper hooks connected to an iron Ppig 3 railing. The student observed, that as these frogs' legs were moved by the wind, or other cause, so as to touch a lower part of the iron grating, they would at the same instant become " convulsed" and exhibit a peculiar twitching movement, which was repeated at every fresh contact, as if still alive. Dr. Galvani immediately commenced a scries of experi- ments, to which he devoted himself almost exclusively for years, producing the same phenomenon in a more and more marked degree, by employing the legs of very recently killed frogs, and the application of certain metals both to the nerve and the muscle of the mutilated animals. Shortly after the announcement of this discovery by Professor Galvani, this marvellous experiment was repeated by various scientific men in Europe, as well as in this country, as a curi- ous circumstance. It appears that Galvani repeated and varied his experiments on the legs and nerves of the mutilated frog, again and again, for five successive years, before he put forth to the world the fact, and his explanation of it. But the very next year after the publication of this wonder of that day, Professor Volta, of Pavia, having set himself at once to the repeating this and other analogous experiments, publicly declared that he had arrived at a new and different conclusion as an explanation of the twitchings of the legs of the recently killed frog. He showed that the electricity was elicited from the contact of two dissimilar metals, while the contraction of the muscles of the frog was only an index of its existence. This explanation of Volta con- tained also substantial and important truth ; but, from the heat