ELECTRIC DISCHARGE WITH THE CHLORIDE OF SILVER BATTERY. 109' 
Description of the Battery and its Working. 
We now proceed to give some account of the battery, of the working of which we 
have had nearly three years’ continuous experience. 
As originally constructed, the chloride of silver battery had open cells, and the zinc 
element was amalgamated ;* since then we have constructed batteries in which the 
cells (tubes) were closed with vulcanised rubber stoppers, perforated to admit of the 
insertion of the zinc rod, the silver wire connected with the chloride of silver was inserted 
between the stopper and the side of the tube, it being previously covered with several 
folds of thin sheet gutta-percha to protect it from the action of sulphur in the vulcanised 
stopper. The amalgamation of the zinc has the advantage of preventing, to a great 
extent, the strong adherence of the oxychloride of zinc to which we have referred in an 
early part of the paper, but presents the great disadvantage of amalgamating and ulti- 
mately rotting the thin flattened silver wire ;t so that having to choose between two evils, 
Fig. 30. 
we have preferred not to amalgamate the zinc when it is intended to keep the batteries 
one or more years in action. Fig. 30 shows a nest of 20 rod cells of the most recent 
construction already described,! but of which we have not before given any drawing. 
The several components of the battery are shown at the base of the stand : Z, the zinc 
rod with the plugy>, inserted in a hole at the right-hand end ; AgCl, the chloride of 
silver rod, cast on the flattened silver wire SW ; Vp, a vegetable parchment cylinder, 
open at both ends and perforated towards the top with two holes to admit of the silver 
wire SW being interlaced through them, as shown in the figure immediately above it ; 
* Journal of the Chem. Soc., new series, vol. vi., entire series, vol. xxi. p. 488, 1868. 
t Platinum, which would not amalgamate, might be substituted, but it would cost £55 extra per 
1000 cells. 
t Proc. Roy. Soc., vol. xxiii. p. 357. 
