272 Mr. Grove on the Gas Voltaic Battery. 



tained each about l£ cubic inch ; in the first form (figs. 1 and 

 8), the portion o, r of the narrow tube contained l£ cubic inch, 

 Fig. 6. Fig. 7. 



\o o\ V2. oh. 



Fig. 8. 



and the portion h, r 1 of the wide tube contained 2^ cubic inches. 

 A portion of the apparatus with which I wrought was con- 

 structed by my order for the London Institution, and another 

 portion belonged to Mr. Gassiot, and was by him very kindly 

 placed at my disposal for the purpose of these experiments ; 

 had it not been for this valuable addition, I should have been 

 obliged to make all my experiments on a much smaller scale ; 

 they would have taken more time and been by no means so 

 satisfactory. 



As I have already stated, a third 

 form has occurred to me while writing 

 this paper, which I think in many re- 

 spects more advantageous than either 

 of the two preceding, and which, as 

 it may be some time before I can ex- 

 periment with it myself, I will here 

 describe for the benefit of those who 

 are differently situated. One cell of 

 it is shown in fig. 8: a, a, is a Woulfe's 

 bottle with three necks ; in the centre 

 neck is fitted a glass stopper, b; in 

 the other two the tubes o, h fit accu- 

 rately by means of glass collars (c c, 

 fig. 9) welded to them and ground on 

 the outside ; the platinum is hermeti- 

 cally sealed into the lops of the tubes, 

 which may be charged in a similar 



