THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JV OV EMBER 1886. 



XLVIII. On the Electrolysis of Silver and of Copper, and the 

 Application of Electrolysis to the Standardizing of Electric 

 Current- and Potential-meters. By Thomas Gray, B.Sc, 

 F.R.S.E* 



[Plate VII.] 



THE following paper contains an account of a large num- 

 ber of experiments on Electrolysis, and on its application 

 to the standardizing of electrical measuring instruments, which 

 have been made during the past year in the Physical Labora- 

 tory of Glasgow University: it forms a summary of the reports 

 which have been from time to time made to Sir William 

 Thomson on the subject. The primary object of most of the 

 earlier experiments was to obtain the value, in absolute measure, 

 of the indications of ampere- and volt-meters ; but these ex- 

 periments were always taken advantage of for the purpose of 

 investigating the reliability of the method under various cir- 

 cumstances as to treatment, size of plates, density of solution, 

 and so on. Many of the later experiments were made specially 

 for the purpose of investigating points of interest suggested 

 by the earlier experiments. It should be borne in mind, with 

 regard to the conclusions put forward in this paper, that 

 they have not been arrived at simply as the result of the ex- 

 periments made personally by the writer, but that he has had 

 the advantage of seeing the methods applied by several inde- 

 pendent experimenters in this laboratory and of comparing the 

 results they obtained. 



The electrolysis of copper has for several years been occa- 



* Communicated by Sir William Thomson, F.E.S. 

 Phil. Mag. S. 5. Vol. 22. No. 138. Nov. 1886. 2 E 



