Electro-therapeutics: a condensed manual of medical electricity / By D. F. Lincoln.

  • Lincoln, David F. (David Francis), 1841-1916.
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: Electro-therapeutics: a condensed manual of medical electricity / By D. F. Lincoln. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    muscles which happen to be aroused by offshoots from the main current. Thus, if we are at work upon the extensors of the hand and fingers, we may observe the hand first shut with a quick impatient movement, and directly afterwards open with a slower motion; and more singular still, we may find the extensors remain- ing more or less contracted for a minute or more, if we do not shut off the galvanic current. But a very power- ful galvanic cuiTent applied to a superficial motor nerve, in a state of perfect health, will also produce a tonic contraction of muscles, as may easily be shown upon the nerves of the forearm. A healthy muscle reacts promptly when the electrodes are applied to its substance; it is believed in this case to respond to the indirect stimulus of its intra-muscular nerves, and not to a stimulation of its independent or Hallerian irritability. A muscle which, through exhaustion, has lost the power to contract, may regain its power if an uninter- rupted galvanic current is passed through it. If ex- hausted by previous galvanization, the direction of the current should be the opposite of that which caused the exhaustion. The same is true of nerves. In the prac- tical applications of electricity, similar results are of constant occurrence, and are often testified to by the sensations of refreshment experienced by patients, in cases where no muscular contractions have been pro- duced. A very important phenomenon attending muscular contraction is the evolution of heat, which, in the case of muscles kept in a tetanic state by means of the faradic current, is very considerable, amounting in one instance1 1 Ziemssen, op. cit., p. 100.