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

he heard a sound, or rather a noise, like scratching and bubbling, or like that of a viscid substance boiling. This noise was con- tinuous and without interruption, becoming even more and more intense until the circuit was broken." It was the muscle contractions that were observed at the clos- ing and opening of the circuit, and particularly the latter, that attracted the greatest attention from Dr. Volta. He errone- ously supposed the latter to be due to a sort of counter-current from a kind of induction, that flowed back on the instant of opening the circuit. M. Lehot, in 1801, modified this theory of Volta's, by laying down the proposition, that during the passage of an electric current through a nerve, a part of the accumulated electricity in the nerve and muscle, at the inter- ruption of the continuous current, flowed at that instant in the opposite direction to which it entered, and so giving rise to the contraction, the same but in less degree as when the current was first closed. This was also erroneous. But the illustri- ous physician and philosopher Volta gave to these phenomena the term " opening- and closing- convulsions," and which are often found referred to by writers. It was Dr. Luigi Galvani, of Bologna, who first discovered that kind of contraction of the muscles of a frog that constitutes the closing convulsion; * while it was Dr. Valli, another Italian philosopher, who soon after- wards made the discovery of the opening convulsion.^ But after all, we can go a long way back of all this to find the first tangi- ble case recorded of the physiological effects of galvanic electri- city ; for, in a paper published by M. Sulzer, in the Reports of the Berlin Academy of Sciences, in 1754, he says, " If a piece of lead and a rod of silver are connected with each other, and approximated to different parts of the tongue, a sensation of taste is experienced which resembles that produced by the vitriol of iron; while, if we employ either of the metals alone, not the slightest taste is perceived. It is probable, therefore, that by the connection of the two metals, a vibration is produced in the smallest particles, either of the lead, or of the silver, or in both * De Vinous Electricitatis in Motu musculari Commentarius. Bologna, 1791. t Reinhold, Gescliichte des Galvanismus, etc., 1792.