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

ings of the different currents on the living organism in a therapeutical point of view, and substantial truths will soon accumulate; but we must first patiently investigate what has already been done. M. Marianini, in 1829, and Nobili, in 1834, were the first to take up Volta's researches for thorough investigation. Maria- nini at once declares himself at some difference from Volta's views, because he supposed he found a difference in the opening- convulsion ; i. e., the twitching that occurs on opening the cir- cuit ; and this according to whether the current flows through the muscle, or whether it flows through the nerve trunk. The former he termed idiopathic, the latter symptomatic convul- sions. In the first case, he thinks that each current direction, and in the latter merely that one running opposite to the ner- vous ramification, will admit of an opening convulsion. When the current courses through the nerves in a direction contrary to that of their ramifications, it will produce, instead of a con- traction, a sensation; but when in the same direction as the nervous ramification, i. e., down-running, it will cause the contraction. Such researches and results are all the more important and interesting, because they were for the first time obtained, not from the amputated frog legs, but from trials made on the live frog, with the loins necessarily separated transversely, so that the legs were connected with the body only by the large nerves. Thus, when a current was directed upward through the nerve, it produced at the opening of the chain a convulsion. If the direction of the current was changed so as to run down, it occa- sioned at the opening of the chain merely a cry from the frog; but this did not invariably appear. As in those times, the the- ory of C. Bell, or the microscopic structure of the nerves, were not as yet known, it is no wonder M. Marianini did not more fully see the prodigious bearing of these results of his own researches, but which our present knowledge proves them to deserve; namely, that the down-running current affects the sensitive nerves more than it does the motory nerves ; and that also the opening of the down-running circuit is felt merely in