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

a nervo-voltaic process; and also, perhaps, by artificial galvan- ism. Dr. Smee says, considering the vast power of muscular fibre produced simply from the apparently small amount of voltaic force, it appears as if muscle is a kind of minute com- pound voltaic battery of membranous cells,—just such as, indeed, we make use of in electro-metallurgy for obtaining many equivalents of results from one equivalent of force. We find alternate minute blood vessels and ultimate sarcous fibre, every alternation of which might be interpreted as one voltaic cell. It is become a current opinion among physiologists that a muscular contraction ensues from an intermittent, natural nervo- electric current. This is demonstrated on the leg of an animal by vivisection: if we cut all the muscles of the limb of one kind, as all the flexors, for instance, or, leaving them entire, and cutting across all the extensors, then, by applying the con- tinuous steady current of galvanism, we obtain, and even main- tain, a continuous contraction for flexion or extension ; i. e., as long as the current flows. This muscular action is repeated as often as is the electric current. M. Ampere lays down the law that each atom of matter pos- sesses an electricity proper to itself; that this may be either positive or negative, and that in a state of equilibrium, for it is always surrounded by an atmosphere of electricity of a con- trary nature to its own, which disguises the latter. But this may not be invariably true. M. Berzelius held that each atom has two electric poles, — one positive and the other nega- tive,— which most beautifully illustrates and unravels indeed many chemical and electro-chemical phenomena. M. De la Rive admits that each molecule not only has two electric sides, hut also a natural polarity. Setting out, then, from this primitive law of the polarity of the atom, it is easy for us to deduce from it, according to the known laws of electricity, the manifestations of bodies under the action of closed electric currents. But we must observe that all philosophers agree in recognizing the difference between the chemical atom and the physical molecule; i. e., that the mole-