ON GALVANIC PHENOMENA. <27J 



" the one being relatively positive, the other negative; which 

 «* has been shown to be perfectly -untenable.''* 



Though Dr. Maycock mentions here the galvanic pile 

 invented by Volta, he does not appear to have used it in 

 his galvanic experiments, for he never speaks but of the ap- 

 paratus of troughs : but if he had seen my papers in your 

 Journal, he would have found in them the same effects pro- 

 duced by the galvanic pile, in which the two metals remain 

 in contact during its action. I shall therefore repeat here 

 the most essential parts of these experiments, comparing them 

 with his system ; a comparison which, thus applied, will pro- 

 bably fix his attention. 



A plate in your Journal for June 1810 shows the con- Mr. De Luc> 

 struction of the galvanic pile, which I used in these experi- arrangement. 

 ments, and the paper explains ray motives for that construc- 

 tion. My pile was composed of two columns, in which ternal 

 groups, consisting of zinc and silver plates and wet cloth, were 

 contained ; but the order of the succession of the Petals was 

 inverse in the two columns; and thus, by means of a brass 

 slip placed at the bottom, they were united in one pile, the 

 extremities of which were both at the top of the apparatus, 

 each connected with a gold leaf electrometer ; which arrange- 

 ment gave the facility of bringing the chemical experiments, 

 in the glass tubes with water, more in sight. 



I made the analysis of the effects of this pile by three dif- h, s an ,i v3 ; s f 

 ferent separations or dissections of its ternal groups, always the effkts of 

 composed of the two metals and a piece of wet cloth. These e i " e * 

 separations were produced by three small upright brass wires, 

 forming the feet of brass tripods. In the first dissection the 

 ternal groups separated by these tripods were the two metah 

 and the wet cloth between them ; and the effects of this dis- 

 section of the pile being the same as when it was not divided, 

 I shall relate them first. 



These experiments begin at p. 121 of my paper in your Experiments. 

 Journal. I first wetted the cloth with pure water: the pile 

 produced the divergence of the gold leaves, and the gasset 

 appeared in the water of the glas9 tubes ; but not the shock; 

 a very remarkable galvanic phenomenon, which Dr. May- 

 cock has not considered, though it leads to the real cause of 

 the chemical effects of the pile, namely, that a liquid must 

 U 2 separate 



