On the Composition oj the Muriailc A<.id. Hi 



introduced into this tube, plunging them into the water at 

 about 0-006 parts of a meter distant the one from the other. 

 This lube was placed upon a horizontal pile of fifty double' 

 plates of about 0-081 parts of a meter :a dimension upon 

 each side. The intervals were fiHed with drv sand, moistened 

 with river-water acidulated with about a sixtieth part of nitric 

 acid. The gold wires having been placed in communication 

 with the two poles of the pile, the water in the tube assumed, 

 from the first day, a reddish brown colour upon the side of 

 the copper pole, and the wire whieh joined it was covered 

 with a coating of a deep brown oxide of gold. The wire 

 corresponding with the zinc pcHe did not assume the same 

 colonr. The gold was gradually dissolved, and was preci- 

 pitated, as well as a portion of the silver alloy. This preci- 

 pitate presented to the magnifying glass, upon almost the 

 whole length of the tube, needle-formed crystals. The wire 

 corresponding with the zinc pole was entirely cleared of the 

 gold which it contained, and it was now nothing else than a 

 silver wire of extreme tenuity. There was very little gas 

 disengaged from either extremity of the wires. The water 

 was only diminished a fifth part of its volume. The pile was 

 in full activity from the 28th Messidor to the 8th Fructidor: 

 it still indicated to the last day, by means of the electro-mi- 

 crometer (simplified and perfected by one of the members of 

 the society upon the one constructed in Germany, described 

 in the Journal de Physique for the month of Messidor, 

 year 13), a tension of 840 degrees. The liquid residue pre- 

 sented with the diflerent re- agents no mark of aciditv, it 

 only had a metallic taste. 



The Galvanic Society, by examining principally the re- 

 sults of the first experiment, as relating more particularly to 

 the fact announced by M. Pacchiani, considered that, hy 

 keeping account of the small quantity of oxygen which had 

 produced the oxidation of the extremities of the gold wire, 

 they might estimate the total quantity of oxygen contained 

 in the gas of the pile; and, as they found it very nearly in 

 the same proportion that oxygen gas enters into the forma- 

 tion of water, the society believed they might conclude tliat 

 the only effect of tl)e action of the Galvanic pile, during'ihe 



whole 



