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IY. Additional Notes on Secondary Batteries. By Dr. J. H. 

 Gladstone, F.R.S., and W. Hibbert, F.LC* 



DURING the publication of a series of papers by Dr. 

 Gladstone and Mr. Tribe in 'Nature/ 1882, on the 

 " Chemistry of the Plante and Faure Accumulators," a dis- 

 cussion arose as to whether the sulphate of lead, to which 

 they attributed so important a part in the reaction, could be 

 reduced by electrolysis. It was shown at the time by expe- 

 rimental proof that this was possible, even when the sulphate 

 of lead was pure, and it was contended that when intimately 

 mixed with peroxide of lead, as in actual practice, there was no 

 difficulty about the matter f. 



There arose, however, a belief that a subsulphate of lead 

 was produced on the plates. Some experimenters found in 

 this belief an explanation of the difficulty in reducing those 

 masses of salt which occasionally form in practice, while others 

 looked upon the subsalt as more easily reducible than the 

 neutral compound. 



So far as we are aware, no specimen of the supposed sub- 

 salt was described till Professor Frankland published his paper 

 in the Royal Society's Proceedings, 1889, vol. xlvi. p. 301, in 

 which he gives an account of what he believes to be two 

 definite subsulphates. That produced from litharge we have 

 already examined in our paper of last June J. Since then we 

 have turned our attention to the other possible subsalt made 

 by the action of sulphuric acid on minium. 



In the original paper §, Gladstone and Tribe gave the formula 

 of decomposition as 



PbA + 2H 2 S0 4 =Pb0 3 + 2PbS0 4 + 2H 2 0. 



They showed by means of a quantitative experiment its 

 gradual slow formation, and said, "It is evident that in a 

 Faure battery we are dealing with plates that consist of a 

 superficial layer of mixed peroxide and sulphate of lead." 



Frankland, while viewing this red substance as a sub- 

 sulphate, arrived at precisely the same ultimate composition, 



* Communicated by the Physical Society : read November 28, 1890. 

 t See " The Chemistry of the Secondary Batteries " in ' Nature ' 



t Phil. Mag. Aug. 1890. and Proc. Phys. Soc. x. p. 448. 

 § See volume cited, p. 14. 



