418 Professor Grove on a Gaseous Voltaic Battery. 



gases. I still think this would be the best mode of effecting 

 the object ; but as it was very troublesome in manipulation, 

 I determined to try the platina platinized by voltaic depo- 

 sition from the chloride, as proposed for a different purpose 

 by Mr. Smee. I therefore caused a series of fifty pairs to be 

 constructed, the form and arrangement of which is given in 

 the annexed figure, where ox denotes a tube filled with oxy- 

 gen ; hy one filled with hydrogen, and the dark line in the 



ow it, 



axis of the tube platinized platina foil, which in the battery 

 I constructed was about one-fourth of an inch wide. It is ob- 

 vious that, by allowing the platina to touch the liquid, the latter 

 would spread over its surface by capillary action and expose 

 an extended superficies to the gaseous atmosphere. The bat- 

 tery was charged with dilute sulphuric acid, sp. gr. 1*2, and 

 the following effects were produced : — 



1st. A shock was given which could be felt by five persons 

 joining hands, and which when taken by a single person was 

 painful. 



2nd. The needle of a galvanometer was whirled round and 

 stood at about 60° ; with one person interposed in the circuit 

 it stood at 40°, and was slightly deflected when two were in- 

 terposed. 



3rd. A brilliant spark visible in broad daylight was given 

 between charcoal points. 



4th. Iodide of potassium, hydrochloric acid, and water 

 acidulated with sulphuric acid were severally decomposed ; 

 the gas from the decomposed water was eliminated in sufficient 

 quantity to be collected and detonated. The gases were evolved 

 in the direction denoted in the figure, i. e. as the chemical 

 theory and experience would indicate, the hydrogen travelling 



