Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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strated that the blood vessels, including both the arteries and the veins, of the thigh of a living animal, as of a frog or rabbit, which has been subjected to the immediate action of a very " strong current of induction " for some ten minutes, do then actually dilate. It has been thought that we are therefore justi- fied in expecting, at least, with this temporary enlargement of the vessels of the muscles, a proportional increase in the supply of blood and nutriment from such treatments. But the nature of this dilatation of the vessels is a question to bo considered. When a weaker current is brought to bear upon the muscle, and for a shorter time, and that through the border point, — which means, simply, through its motory nerve, — it is equally certain that the blood vessels are both dilated and contracted by the different influences of the current. Therefore the intra- muscular excitement of the nerve fibrils and muscle fibres, as well as the vessels through the border spot or nerve, is al- ways preferable, or, at least, is less objectionable, particularly wherever we wish to avoid those undesirable motory or sensitive by-workings which generally accompany the excitement of the larger nerve trunks. We know we can contract and momenta- rily tetanize the facial muscles as a whole, in groups, or singly, and that without causing much pain from the nerve trunk of the portio dura, or its large primary branches. Drs. Duchenne and Remak have both of them Faradaizcd the diaphragm of man, the former operating through the phrenic nerve. The latter says, " The diaphragm seems to be a partici- pator in the acts of respiration even more than any other of the thoracic muscles, and is susceptible to immediate electric excite- ments. I have produced by Faradaic currents, on some healthy young men, instantaneous, violent, and painless contractions of the diaphragm, which were indicated by the vaulting of the ab- dominal parietes on placing one electrodo ' in the pit of the stomach,' while the other was on the most prominent curvature of the seventh and eighth ribs on the right side. It was interesting to observe the phenomenon while the currents were retained there, for, immediately after the current was applied, the tonic contraction (which was inferred from the arching of the abdomen)