2iO HISTORY OF GALVANISM. 



described in the Philosophical Transactions for 1800, completely 

 satisfies this aspiration ; and was, in fact, a more important step in the 

 history of electricity than the Leyden jar had been. It has since 

 undergone various modifications, of which the most important was 

 that introduced by Cruikshanks, who 4 substituted a trough for a pile. 

 But in all cases the principle of the instrument was the same ; a con- 

 tinued repetition of the triple combination of two metals and a fluid 

 in contact, so as to form a circuit which returns into itself. 



Such an instrument is capable of causing effects of great intensity , 

 as seen both in the production of light and heat, and in chemical 

 changes. But the discovery with which we are here concerned, is not 

 the details and consequences of the effects, (which belong to che 

 mistry,) but the analysis of the conditions under which such effects 

 take place; and this we may consider as completed by Volta at the 

 epoch of which we speak. 



CHAPTER II. 



RECEPTION AKD CONFIRMATION OF THE DISCOVERY OF VOLTAIC 



ELECTRICITY. 



GALVANI'S experiments excited a great interest all over Europe, in 

 consequence partly of a circumstance which, as we have seen, was 

 unessential, the muscular contractions and various sensations which 

 they occasioned. Galvani himself had not only considered the animal 

 element of the circuit as the origin of the electricity, but had framed 

 a theory, 1 in which he compared the muscles to charged jars, and the 

 nerves to the discharging wires ; and a controversy was, for some time, 

 carried on, in Italy, between the adherents of Galvani and those of 

 Volta. 2 



The galvanic experiments, and especially those which appeared to 

 have a physiological bearing, were verified and extended by a number 

 of the most active philosophers of Europe, and especially William 

 von Ilumboldt. A commission of the Institute of France, appointed 

 in 1797, repeated many of the known experiments, but does not seem 

 to have decided any disputed points. The researches of this coimnis- 



4 Fischer, viii. p. CSS. ' Ib. viii. 613. " Ib. yiii. 619. 



