Page:Popular Science Monthly Volume 41.djvu/422

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408
THE POPULAR SCIENCE MONTHLY.

forgets that all the lava that flows to the surface comes from the depths of the crust, where its departure leaves a void which can be compensated for only by the depression of the adjoining territory to such an extent that the emerged relief really gains nothing. More than this — volcanic action, which M. Léotard would make creative, is really, above everything else, destructive. I ask no better proof of this than the great explosions of which the nineteenth century has been the witness; that of 1845, at Temboro, which covered the neighboring country and the surface of the sea with a mass of débris estimated at a hundred cubic kilometres; and the more recent eruption at Krakatoa, which threw into the Strait of Sunda eighteen cubic kilometres of débris and formed an abyss between two and three hundred metres deep, in a place where there had previously stood a volcanic mountain several hundred metres high. While I have felt called upon to make this rectification, I will add that that does not prevent me from believing, with M. Léotard, that the final triumph of the dry land is infinitely more probable than its submersion; and that by reason of the considerable movements of the crust and the wrinkles which lateral compression in consequence of the progress of cooling can not fail to engender from time to time."


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SKETCH OF LUIGI GALVANI.

THE experiments of Galvani were the beginning of a new course of development in physical science, the fruits of which promise to be infinite in number and of incalculable magnitude and importance.

Luigi Galvani was born in Bologna, Italy, September 9, 1737, and died in the same place, December 4, 1798. He exhibited when very young a fervent zeal for the Catholic religion, of which he was exact in observing the most minute rites. He even thought of going into a monastery, but was diverted from his intention, and, while his religious inclinations were still prominently marked, he became interested in scientific pursuits. Entering upon the study of medicine, he gave his attention chiefly to anatomy and physiology — human and comparative. Having successfully maintained a thesis on the Bones, their Nature and Formation, he was appointed, in 1762, public lecturer on anatomy at the University of Bologna, where he became known as a skillful and accurate teacher, though not eloquent in address. Along with his professorship he gained high repute as a surgeon and childbed doctor. He produced during the earlier period of his professional career a number of memoirs of considerable merit,