Loss of Voltaic Energy of Electrolytes. 



353 



In conclusion, I desire to express my thanks to Mr. John 

 Gavey, of the S. Wales Telegraphic Department, for the help 

 he has rendered me in connexion with this matter. 



University College, Cardiftj 

 March 22nd, 1889, 



XLII. On the Loss of Voltaic Energy of Electrolytes hy 

 Chemical Union. By Dr. Gr. Goke, F.R.S.* 



IN a research on the " Influence of the Chemical Energy 

 of Electrolytes upon the Change 

 of Potential of a Voltaic Couple in 

 Water '^ (Proc. Eoy. Soc. 1888, 

 vol. xliv. pp. 300-308) I have shown 

 that the minimum proportions of 

 various substances required to change 

 the potential of a voltaic cell of un- 

 amalgamated zinc, platinum, and 

 distilled water, when balanced by a 

 perfectly similar cell, and to visibly 

 move the needles of an ordinary 

 astatic torsion galvanometer of 

 100 ohms' resistance (see sketch) 

 were as follows : — 





Table I. 







Minimum 



Proportion. 





Chlorine . 

 Bromine . 

 Iodine . 



Between 1 part in 

 . 1,264,000,000 and 

 77,500,000 

 3,100,000 



Parts of Water 



1,300,000,000 



84,545,000 



3,521,970 



Average. 

 1 part in 



1,282,000,000 



81,022,500 



3,310,985 



KCl ... 

 KBr ... 

 KT 



695,067 

 66,428 

 15,500 



704,540 

 67,391 

 17,222 



699,803 

 66,909 

 16,361 



KTO3 . . . 

 KBrO, . 

 KCIO, . 



443 

 344 

 221 



494 

 384 



258 



468 

 364 

 239 



* From the Proceedings of the Birmingham Philosophical Society, 

 vol. vi. part 2. Communicated by the Author. 



Phil. Mag. S. 5. Vol. 27. No. 167. April 1889. 2 A 



