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

disturbance of the element of motion and sensation. The nerve, indeed, becomes polarized, pile-formed, or in pyramidal order, which is the electro-tonic condition. When both poles of the battery are removed, and the current is thus opened, the electro- tonic condition of the nerve-conductor disappears, and the mole- cules return from the induced di-polar to the natural polar state of a healthy nerve; whereby we see manifested the same contrast between the closing and the opening convulsion as between the closing and opening current, viz., the closing convulsion shows by the down-running currents the same peculiarities which the open- ing convulsion presents by the up-running current, and vice versa. Dr. Robert Remak, of Berlin, says, that although Dubois- Reymond has produced and shown the electro-tonic state of the nerves, even when he used interrupted currents for exciting them, nevertheless, we arc by no means allowed to suppose that the action of the interruption did, in itself, contain the cause of the induced condition of the nerves. On the contrary, he says, Dubois-Reymond shows, by a long series of the most careful experiments, that the result of the tetanizing of the nerves by alternating currents, and even of the tetanus produced in those which cannot be electrized in consequence of strychnine, or other chemical hinderance, is a negative fluctuation of the native nerve-current. Therefore it is made probable, by comparing all the conditions under which, on the one hand, convulsions appear, and on the other, where negative stream fluctuations are shown to be in the nerves ; that this negative fluctuation is the true electro-motory expression of the element, or cause, of mo- tion and sensation, which appears in the nerve whenever its inner equilibrium is disturbed by mechanical, caustic, or chemi- cal causes, or every time it is placed by an exciting current into the electro-tonic condition. Finally, that this condition undergoes a certain fluctuation in consequence of a similar fluctuation of the exciting electric cur- rent, the density of which stands within certain limits, and that in a simple ratio to the strength of the electro-tonic condition. In view of such intensely interesting facts, Dr. Remak most justly says, " How the field of the physiological pre-trials and