THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



MARCH 1844. 



XXVI. Further Observations on the Voltaic Decomposition of 

 Solutions. By Arthur Connell, Esq.* 



\ FEW years ago I published a set of experiments on the 

 ** galvanic decomposition of solutions of binary combina- 

 tions, such as acids or alkalies, in water and solvents contain- 

 ing water as a constituent-}-; and drew the general conclusion 

 that in such cases the water of the solvent alone suffers the 

 direct agency of the current. This rule of course did not in- 

 clude solutions of ordinary salts, in which the dissolved salt 

 was admitted to be resolved into its constituent acid and alkali 

 by direct voltaic action, at the same time that water was di- 

 rectly decomposed; but I stated that when an aqueous solu- 

 tion of certain metallic salts, such as sulphate of copper, was 

 made positive, and distilled water in a different vessel was made 

 negative by a power of fifty pairs of two-inch plates, the con- 

 nection being by asbestus, neither metal nor oxide was ob- 

 served to be formed, whilst on reversal of the battery reduced 

 metal immediately appeared on the negative foil now in the 

 solution of the salt, in virtue, as I conceived, of the reducing 

 action of nascent hydrogen arising from decomposed water. 



This experiment was perfectly accurate with reference to 

 the circumstances under which it was made. About the same 

 time Professor Daniell varied those circumstances so as to 

 admit of a much more powerful voltaic agency, by using so- 

 lution of potash instead of distilled water, and separating this 



* Communicated by the Author. 



f Vol. xviii. of this Journal, S. 3. p. 241. It seems that it is not altogether 

 superfluous to state, that I did not hold in the memoir referred to, as has 

 been sometimes imagined, that water is the only compound body which is 

 decomposed by electrical agency. I spoke of solutions only, whilst every 

 body knows that Mr. Faraday has proved that many dry and fused oxides 

 and haloid salts are decomposed by the galvanic current. 



Phil. Mag. S. 3. Vol. 24. No. 158. March 1844. M 



