70 Galvanism > from Galvani to Ohm. 



kind of metal ; and he advanced the hypothesis that the convul- 

 sions are caused by the transport of a peculiar fluid from the 



' nerves to the muscles, the arc acting as a conductor. To this 

 fluid the names Galvanism and .Animal Electricity were soon 

 generally applied. Galvani himself considered it to be the same 

 as the ordinary electric fluid, and, indeed, regarded the entire 

 phenomenon as similar to the discharge of a Leyden jar. 



*' The publication of Gralvani's views soon engaged the attention 

 of the learned world, and gave rise to an animated controversy 

 between those who supported Galvani's own view, those who 

 believed galvanism to be a fluid distinct from ordinary electricity, 

 and a third school who altogether refused to attribute the effects 

 to a supposed fluid contained in the nervous system. The leader 

 of the last-named party was Alessandro Volta (b. 1745, d. 1827), 

 Professor of Natural Philosophy in the University of Pavia, who 

 in 1792 put forward the view* that the stimulus in Galvani's 

 experiment is derived essentially from the connexion of two 

 different metals by a moist body. "The metals used in the 



* experiments, being applied to the moist bodies of animals, can by 

 themselves, and of their proper virtue, excite and dislodge the 

 electric fluid from its state of rest ; so that the organs of the 



* animal act only passively." At first he inclined to combine this 

 theory of metallic stimulus with a certain degree of belief in 

 such a fluid as Galvani had supposed; but after the end of 17!. '3 

 he denied the existence of animal electricity altogether. 



From this standpoint Volta continued his experiments and 

 worked out his theory. The following quotation from a lettert 

 which he wrote later to Gren, the editor of the Neucs Journal //. 

 Physik, sets forth his view in a more developed form : 



"The contact of different conductors, particularly the metallic, 

 including pyrites and other minerals, as well as charcoal, which 

 I call dry conductors, or of the first class, with moist conductors, 

 or conductors of the second class, agitates or disturbs the electric 



f fluid, or gives it a certain impulse. Do not ask in what manner : 

 it is enough that it is a principle, and a general principle. This 



*Phil. Trans., 1793, pp. 10, 27. tPhil. Mag. iv (1799), pp. 59, 163, 306. 



