296 Mr. Mi Donovan on the supposed Identity of the Agent 



was introduced into a matrass, and so placed that the two plates 

 stood vertically, and the wire horizontally, when the matrass 

 lay on its side ; and in this position the plates were secured by 

 a little sealing-wax previously adhering to their edges, and now 

 melted by heating the glass. A quantity of dilute sulphuric 

 acid, of which one-third was concentrated acid, being introduced 

 into another matrass with a neck of equal diameter with the 

 former, both necks were joined by melting in a glass-blower's 

 lamp. This done, and the glass cold, the end of the double 

 matrass which contained the acid was elevated until the acid 

 trickled down into that part where the pair of plates was ce- 

 mented, and covered about half the height of the plates, the com- 

 pound vessel lying horizontally on a gold-leaf electrometer, and 

 that part of the matrass being externally coated with tin-foil. 

 The portion of zinc exposed to the acid, i. e. four grains, was 

 dissolved in about two minutes and a half; but the platinum 

 wire was not in the most obscure degree reddened, although 

 examined in the dark, its length and thickness being too great 

 for the heating power of the voltaic combination ; neither was 

 there the slightest effect on the electrometer. 



If, then, according to the supposition which I am endeavour- 

 ing to disprove, the electricity arising from the solution of four 

 grains of zinc, that is, 240 millions positive and negative of one- 

 inch sparks, had passed through the platinum wire, at the rate 

 of 1,600,000 per second, need it be inquired what would have 

 become of the wire, nay, the whole apparatus and the operator ? 

 Van Marum, with one discharge of the great Leyden battery, 

 consisting of 225 square feet of coated glass, melted forty feet 

 of iron wire 2^o* u mcn diameter*. 



From both of these experiments with hermetically sealed 

 matrasses, I infer that no electricity was evolved in a free or di- 

 spersed state during the voltaic solution of four grains of zinc ; 

 that no such quantity of electricity as has been supposed, nor 

 the millionth part of it, passed through the platinum wire. 

 Where, then, are we to look for the enormous quantity of this 

 subtile fluid which is supposed to be the result of the voltaic 

 solution of the zinc ? The supporters of the doctrine here ob- 

 jected to may maintain that the alleged quantity was really in 

 operation during the separation of the elements of the grain of 

 water by four grains of zinc, but that it was retained and con- 

 cealed in the constitution of the resulting gases. This seems to 

 be the opinion of Faraday : he thus expresses himself : " in the 

 combination of oxygen and hydrogen to produce water, electric 

 powers to a most enormous amount are for the time activef." 



* De'script. d'une trfo grande fllach. Elect, a Haarlem. Prciu. Cont. p. 10. 

 t Researches, par. 960. 



