Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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trunks, as they take their exit from the cord. We may sum up the uniform local effects upon the skin and underlying tissues, as being in direct proportion to the efficiency of the machine, the length of the spark, the repetition of these sparks, as well as the delicacy and sensitiveness of the skin of the part operated upon. The electric shock, it is well known, is given from the Ley- den jar; one or more being employed, according to the power required. It is also known that in this arranged jar there can be accumulated a considerable quantity of electricity of the highest tension, and that on a comparatively small surface. The jar can be charged either positively or negatively. To charge it positively, the brass knob at the top of the jar is made to communicate with the prime conductor of the electric machine, while the outer coating communicates with the earth; then some thirty to fifty turns will charge a one-quart Leyden jar. Methods for employing the various Electric Currents. In the more recent German and Italian medical writings we find evidence that some leading men there are giving more special attention to this particular department of " therapeu- tics^ than we find either in Prance, England, or America. Dr. Duchenne, however, was the first to partially recognize the great fact, that there are certain spots along the surface of the body and limbs that give very peculiar response to the electrode in producing more ample muscle contractions without pain. Simultaneously, and still more clearly, was this remarkable cir- cumstance discovered by Dr. Robert Remak, of Prussia. He says, " After numerous trials on the different parts of living men, I am prepared to say that I believe I can explain those spots, or ' border points,' alluded to by Dr. Duchenne, as ob- served by him, but in only two muscles." In a very recent foreign work by Dr. Maurice Meyer, on " The Uses of Electri- city in the Practice of Medicine," published in Germany, there appears the following description of his method : — " To produce electric excitement of the ' motory nerves? or