Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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towards the centre — i. e., where the connection of the nerves was intact. Therefore the terminal branches of the nerves are presumed to be the first which are destroyed by the poison of woorara ; and as, in spite of this destruction of the properties of these terminal nerve fibrils, the muscles still show a ready re- sponse to the galvanic stimulus, the existence of the Hallerian irritability is claimed to be proved. Mr. Bowman, of King's College Hospital, London, has arrived at what he claims to be equally unanswerable conclusions, but in quite a different way. He appeals to direct microscopical observations, made on living fragments of the elementary fibres of voluntary muscles, which he had entirely denuded and insu- lated from every vestige of other substance, whether nerve or vessel, so that he had nothing but the pure muscular fibre.* He observed that if, by design or accident, a particle of foreign mat- ter was included in the field of the microscope, so as to be seen to touch the side of the fibre at a single point, the fibre there exhibited a contraction, that was limited to the point so touched, and not involving the whole muscular substance. Hence Mr. Bowman concludes that the muscles do possess an irritability proper, capable of being brought into action by a stimulus topi- cally applied. It is obvious, says Dr. Althaus, that this observa- tion of Mr. Bowman is of paramount importance, and that it greatly contributes to decide this question. M. Claude Bernard undertook another series of experimental researches on the physiological action of the woorara poison, which also throws light directly upon this subject. He took two prepared frogs, and poisoned one of them by inserting under the skin a small bit of the woorara. At the end of five or six min- utes the frog ceased to show signs of life, and the poison was then withdrawn, and a galvanic current caused to traverse a portion of the lumbar nerve of each of the frogs alternately. The muscles of the frog which had not been poisoned were im- mediately seen to show a powerful contraction, but not the slightest twitching occurred in the other frog. But when the * Dr. Althaus on Jledical Electricity, London, 1859, p. 129.