SECT. IT. OF ELECTRIC DISCHARGES. 85 



This process facilitates the discharge and assists the 

 disintegration of the carbon particles, and these in a 

 minute state of division are subsequently found attached 

 to the sides of the glass. It is these particles which 

 produce the arc discharge with its intense vivid light so 

 suddenly observed with far more brilliant effects than 

 the usual stratified discharge. During its passage the 

 conducting power of the vacuum tube is greatly 

 enhanced. 



It was already mentioned that a stratified discharge 

 was obtained from 3,520 insulated cells of a water bat- 

 tery, which differs but little in intensity from 400 cells 

 of the nitric acid battery. On one occasion the elec- 

 tricity seemed to pass through the vacuum tubes in 

 a continuous stream, but when examined with Mr. 

 Wheatstone's revolving mirror it was decidedly strati- 

 fied. Mr. Gassiot never could obtain a continuous 

 discharge in air, whether between the points or metallic 

 plates of the water battery. The discharge was invari- 

 ably in the form of minute clearly defined and separate 

 sparks. 



Thus it was proved by the preceding experiments 

 that a spark discharge could be obtained in air from 

 both the nitric acid and water battery ; and that when 

 these discharges were passed through the highly at- 

 tenuated matter contained in carbonic acid vacua, the 

 same luminous and stratified appearance was produced 

 as by an induction coil ; a proof that whatever may be 

 the cause of the phenomena it could not arise from any 

 peculiar action of that apparatus. 



Mr. Gassiot finally concludes that the cause of the 

 stratified discharge arising from the impulses of a force 

 acting upon highly attenuated but resisting media is 

 also applicable to the discharge of the voltaic battery 

 in vacuo; while the fact of this discharge even in 

 its full intensity having been now ascertained to be 



