Vol. VI, No. 2.] The Electro-chemical Equivalent of Nickel. 43 



IN. 8.] 



An attempt to interpret these discordant results may not, 

 perhaps, be out of place here before proceeding to bring further 

 experiments to bear upon such variations. The results ob- 

 tained in the preceding experiments leave little room for doubt 

 that the presence of free acid in the electrolyte was responsible 

 for the anomolous values of the e.c.e., and that they went down 

 steadily with increased production of acid in the voltameter, 

 each time the liquid was electrolysed. 



It appeared extremely probable that the comparative in- 

 solubility of the nickel anode was at the root of the irregulari- 

 ties. The sulphions, failing to dissolve the anode as readily as 

 with silver and copper for instance, combined with water to 

 form sulphuric acid. A gradual fall of the e.c.e. at each 

 successive electrolysis and a simultaneous accumulation of acid 

 thus seem to be closely allied phenomena, while the removal of 

 of the acid by neutralization with the carbonate, accom- 

 panied by a corresponding set of higher values of the e.c.e. as 



with 



'i 



that the presence of the acid developed was the immediate 

 cause of these discrepancies. 



Since the amount of free acid produced may be taken to 

 be proportional i to the quantity of electricity passed through 

 the solution, it is clear that, other conditions remaining the 



acid was developed in the pure solution when it 



more 



was 



current -9396 ampere than before, when the current value 

 was "9144 ampere, the solution being neutral to start with in 

 either case. This will account for the worse result with the 

 pure stuff as pointed out above. 



An explanation of the slower rate of fall in the values for 

 the impure stuff, though not quite clear at first sight, will be 

 so on the following considerations. 



The total volume (750 c. c.) of the impure solution was 

 much greater than that of the pure stuff (216 c. c), though 

 equal volumes from each (160 c c.) were taken for the experi- 

 ments. After each electrolysis the solutions were put back into 

 their respective stock bottles. The result was that the amount 

 of acid liberated in an experiment became diluted (very largely 

 so in the case of the impure stuff) in the bottles before the 

 solutions were electrolised for the next time. The larger dilu- 

 tion of the acid in the impure stuff very much enfeebled it 

 effect at the time of experiment, and the fall in the value of the 



was 



Effect of Repeated 



To examine more 



the acid generated during 



51 Q •fz-vll^.— .«-. 



as follows. 



systematically the cumulative eff 

 ing electrolysis, experiments were 



effect of 

 made 



