1881.] on the Phenomena oj the Electric. Discharge. 4G3 



siderably greater than that of any battery liitlierto united in series. 

 The illustrious Sir Humphry Davy used in 1808, in this theatre, a 

 battery of 2000 plates 4 inches scjuare, with double plates of copper, 

 the battery bein^ cliarged with a dilute mixture of suljdiuric and 

 nitric acids. With this magnificent instrument, placed at his disposal 

 by the subscriptions of a few patrons of science, he obtained a spark 

 of an inch, when the terminals were made to approach each 



Fig. 2. 



".,('•'■'■ \. I . ' , ':uriili;iliiJ::iU:;i,llj!liiiili!i:lllii:!:ilji'!l;^^^^^^^^^ P''H!iiiill,;!'i'.M'!:i]|"iii"i!',„i:!!"i!i!iiiii„H'M%:;i , 



TVto 



Other (a striking distance of ^\ of an inch would accord with our 

 experiments with the chloride of silver battery, if the difference of 

 potential of the two batteries is taken into account). When the 

 discharge had once taken place, then the terminals might be separated 

 4 inches without causing its discontinuance. 



My friend the late Mr. Gassiot constructed several batteries of 



2 K 2 



