Galvanism, from Gaivani to Ohm. 75 



ductors exists all round the circuit, and that the current is 

 suspended only when this communication is interrupted. 

 " This endless circulation or perpetual motion of the electric 

 fluid," he says, "may seem paradoxical, and may prove 

 inexplicable ; but it is none the less real, and we can, so to 

 speak, touch and handle it." 



Yolta announced his discovery in a letter to Sir Joseph 

 Banks, dated from Como, March 20th, 1800. Sir Joseph, who 

 was then President of the Eoyal Society, communicated the 

 news to William Nicholson (b. 1753, d. .1815), founder of the 

 Journal which is generally known by his name, and his 

 friend Anthony Carlisle (b. 1768, d. 1840), afterwards a 

 distinguished surgeon. On the 30th of the following month, 

 Nicholson and Carlisle set up the first pile made in England. In 

 repeating Volta's experiments, having made the contact more 

 secure at the upper plate of the pile by placing a drop of water 

 there, they noticed* a disengagement of gas round the con- 

 ducting wire at this point ; whereupon they followed up the 

 matter by introducing a tube of water, into which the wires 

 from the terminals of the pile were plunged. Bubbles of an 

 inflammable gas were liberated at one wire, while the other 

 wire became oxidised ; when platinum wires were used, oxygen 

 and hydrogen were evolved in a free state, one at each wire. 

 This effect, which was nothing less than the electric decom- 

 position of water into its constituent gases, was obtained on 

 May 2nd, 1800.f 



Although it had long been known that frictional electricity 

 is capable of inducing chemical action,* the discovery of 

 Nicholson and Carlisle was of the first magnitude. It was at 

 once extended by William Cruickshank, of Woolwich (b. 1745, 



i's Journal (4to), iv, 179 (1800) ; Phil. Mag. vii, 337 (1800). 



t It was obtained independently four months later l>y J. "W. Hitter. 



J Beccaria (Lettere deW elettricismo, Bologna, 1758, p. 282) had reduced mercury 

 and other metals from their oxides by discharges ot fractional electricity ; and 

 Priestley had obtained an inflammable gas from certain organic liquids in the 

 same way. Cavendish in 1781 had established the constitution of water by 

 electrically exploding hydrogen and oxygen. 



