1884.] On the Electrolysis of Dilute Sulphuric Acid, fyc. 215 



Somewhat similar experiments have also been made with glass tubes 

 with negative results. 



The author has also made a few experiments to ascertain the 

 influence of a voltaic current in increasing or diminishing the flow of 

 hydrogen through the medium, but so much depends upon the struc- 

 ture of the metallic surfaces in contact with the medium and their 

 relative sizes, as well as upon the electromotive force, &c, of the 

 battery used, that this subject would probably require somewhat 

 elaborate researches. 



The author, however, hopes to make further investigations into the 

 nature of the movements of hydrogen produced in vitreous matters 

 and in metals. 



II. " On the Electrolysis of Dilute Sulphuric Acid and other 

 Hydrated Salts." By J. H. Gladstone, Ph.D., F.R.S., and 

 Alfred Tribe, Lecturer on Chemistry in Dulwich College. 

 Received December 20, 1883. 



On the 1st of March last a communication was presented to the 

 Royal Society by Professor Frankland, in which, among other things, 

 the reactions we had described as taking place in the charging and 

 discharging of secondary batteries were confirmed. The author 

 expressed these reactions, however, by formulae founded on the elec- 

 trolysis, not of H 2 S0 4 , but of hexabasic sulphuric acid, H 6 S0 6 , in 

 accordance with the views of Bourgoin. 



The point of difference is a small one, but it led us to look into the 

 papers of Bourgoin, and to examine the evidence upon which his 

 views were based. The French chemist ("Ann. de Chimie," 1868) 

 treats of the electrolysis of sulphuric acid merely as an illustration of 

 his method for determining the composition of hydrated salts in 

 solution generally. This method consists in electrolysing a given 

 solution in a divided cell, analysing the liquid in each compartment 

 at the close of the experiment, and, in the case of dilute sulphuric 

 acid, collecting the hydrogen set free. In the case of a solution 

 of sulphuric acid, of course, the positive compartment may be ex- 

 pected to increase in strength as a consequence of the electrolytic 

 action, and the negative compartment to decrease in strength in the 

 same degree. Bourgoin calls the increase of the acid in the positive 

 compartment a, and concludes that 2x represents the amount of sul- 

 phuric acid electrolysed. This conclusion rests on the well-known 

 theoretical views of Grotthuss, and, did his theory express all that 

 goes on in the electrolytic process, the method would readily dis- 

 criminate between the actions represented by the following formulae : 



VOL. XXXVI. Q 



