16 THE ELECTRIC TELEGRAPH. 



meet with chances so favourable to advancement as those 

 which directed the attention of Galvani to the study of 

 animal electricity by a phenomenon of electroscopic sensi- 

 bility in the nerves of a frog ; his fortunate ignorance, which, 

 combined with his ardent imagination, caused him to form 

 hypotheses only excellent because, in being stubbornly sup- 

 ported by himself, he added to the stock of facts, through his 

 many and varied experiments, and in occasioning a discus- 

 sion in which his views were successfully refuted by the 

 masterly intellect of Alexander Volta. 



"In der Beobachtung einer anfangs isolirt stehenden 

 Erscheinung liegt oft der Keim einer grossen Entdeckung," 

 says Humboldt ; * and Galvani found it so, and deservedly 

 earned his title of a pioneer in science. 



20. Immediately after the publication of Galvani's dis- 

 covery and hypothesis, Alexander Yolta, professor of physics 

 at Pavia, occupied himself with an inquiry into the causes of 

 the frog phenomenon, and was not long in perceiving a want 

 of basis in Galvani's theory. With much penetration Yolta 

 recognised the intrinsic elements in the complicated appear- 

 ance which Galvani had discovered, and sought, with success, 

 to produce the same by substituting other materials for the 

 frogs and other animal bodies. He contended that the two 

 metals, copper and iron, in the experiment of Galvani, were 

 the real electromotors, and that the muscles of the dead frogs 

 only played the part of a moist conductor in completing the 

 circuit. Yolta was of opinion that the simple contact of 

 two dissimilar metals was sufficient to develop electricity, 

 and that the strength of the electricity excited depended 

 upon the nature of the metals. This was vigorously opposed 

 by the partisans of Galvani, who held tenaciously to the 

 doctrines of their master, and a scientific war of opinions 

 ensued between the schools of Pavia and Bologna, out of 

 which Yolta came victorious even before he had completely 

 verified his sagacious conjectures by experimental proof. 



If the tongue be applied to the conductor of an electric 

 machine which is being turned, an acid or alkaline taste 

 * Cosmos. Einleitende Bemerkungen. 



