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V. Experimental Researches on the Electric Discharge with the Chloride of 
Silver Battery. 
By Warren De La Rue, M.A., D.C.L., F.R.S., and Hugo W. Muller, Ph.D., F.R.S. 
Received August 23, — Read December 13, 1877. 
[Plates 6-8.] 
Part I.— THE DISCHARGE AT ORDINARY ATMOSPHERIC PRESSURES. 
In the ‘Journal of the Chemical Society,’ November, 1868,* we first published an 
account of the chloride of silver battery, which we had devised as one of great 
constancy and well suited for studying the discharge in exhausted tubes ; we shortly 
afterwards carried the number of cells to 200, and presented a battery of 100, part 
of the 200, to our friend the late Mr. Gassiot, who at that time was in search of a con- 
stant battery suitable to his investigations. Mr. Gassiot did not, however, adopt the 
chloride of silver battery, and it remained unemployed until 1874, when, in pursuance 
of a suggestion of our friend Mr. Spottiswoode, we put together for his use 1080 cells, 
but soon found that in order to effectually study the phenomena of the discharge it 
would be necessary to carry the number of cells much higher, this we have gradually 
done, and now possess 8040 cells in actual work, and 2680 more completed but not 
charged with fluid f. Amongst the 8040 cells in actual use are the first 1080 con- 
structed in 1874, so that the constancy of the battery is thereby fully established. 
In the course of the increase of numbers, experience has led to many modifications 
of the details of the battery, but we reserve for the latter part of this communication 
a description of them. On the 24th February, 1 875 J, we gave an account, in 
conjunction with our friend Mr. Spottiswoode, of some experiments made with 
1080 cells, and on the 28th April, 1875, we made a verbal communication to the 
Society of Telegraph Engineers, when the battery of 1080 cells was exhibited. § 
Subsequent to that meeting, our friend Mr. Latimer Clark, called our attention 
to and lent us a small work entitled 4 The Electric Telegraph in British India,’ by 
W. B. O’Shaughnessy, M.D., F.R.S., London, 1853, where, at page 14, the author 
describes an experimental cell of fused chloride of silver, and in justice to him we 
* Journ. CKem. Soc., new series, vol. vi. ; entire series, vol. xxi. p. 488. 
t January 1, 1878. — The extra number now made up and charged is 2960 cells, which brings the total 
up to 11,000 cells. See Supplement, p. 116. 
J Proc. Roy. Soc., vol. xxiii. p. 356. 1875. 
§ Journ. Tel. Engineers, vol. iv., No. XI., p. 202. 1876, 
