Page:Popular Science Monthly Volume 41.djvu/425

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411
SKETCH OF LUIGI GALVANI.

the other with a muscle of a frog, caused contraction of the muscle.

Galvani recognized a great similarity between the phenomena he had observed and electricity, but denied their identity. He thought an electricity of a peculiar nature was concerned in the manifestations, and that he had discovered the nervous fluid. In his view, all animals possessed an electricity inherent in their economy, which resided especially in the nerves, and was communicated by them to the whole body. It was secreted by the brain; the interior substance of the nerves was endowed with a conducting power for this electricity, and facilitated its movement and its passage through the nerves; at the same time an oily coating of these organs prevented the dissipation of the fluid and facilitated its accumulation. The principal reservoirs of this electricity he supposed to be in the muscles, each fiber of them representing a small Leyden jar, from which the nerves were conductors. In the mechanism of the movements the electric fluid was drawn out and attracted from the interior of the muscles into the nerves in such a way that each discharge of the muscular electric jar corresponded with a contraction of the muscle. This theory had many partisans for a considerable time, but was refuted by Volta, who showed, as has been related in our recent sketch of him, that the supposed nervous fluid was only ordinary electricity, to which the animal organs served as conductors, and of which they might even be generators. Galvani did not yield to these arguments of Volta's, but held to his own unsound hypothesis; and thus the glory of making a scientific explanation and application of his great discovery fell to Volta. An account of Galvani's discoveries was published in the Philosophical Transactions for 1793. A quarto edition of his works was published at Bologna by the Academy of Sciences of the Institute of that city in 1841-'42. Perhaps the best and most appreciative accounts of Galvani's life and works are by M. Arago, in Alexandre Volta, in the first volume of Arago's Œuvres Complètes, and the eulogy by J. L. Alibert, Bologna, 1802.

 


 
Mr. A. Wilkins, of Tashkend, central Asia, had a specimen of the typical desert bird of the country (Podoces panœri), which, on the first day of its life with him, buried a part of the food given it in the sand with which the floor of the cage was covered. On the next day, and afterward, the bird abandoned the habit on perceiving that the supply given it did not fail. Another correspondent of Nature had a fox-terrier puppy, seven weeks old, which had not seen any other dog but its mother, that buried bones in the garden with great skill. It dug a hole with its fore paws, put in the bone, pushed it down with its nose, and covered it with garden soil which was pushed in with its nose. He had never seen so young a puppy bury bones, or any other dog do it so well.