VOLTAIC ACTION OF PHOSPHORUS, ETC. 295 



voltaic excitants ; as, if my view of the volatility of phos- 

 phorus and sulphur were correct, other volatile bodies ought 

 to act similarly. Camphor was the first substance I experi- 

 mented on. A piece of camphor weighing 12*9 grains was 

 placed in a similar manner to the phosphorus (33) in nitrogen, 

 and associated with oxygen ; tested by the galvanometer it 

 gave a feeble deflection, which, however, was continuous ; it 

 was allowed to remain four months in closed circuit ; at the 

 expiration of that time the liquid had risen in the oxygen 

 tube O'3 cubic inch ; the nitrogen in which the camphor was 

 suspended had increased in volume 0*15 of a cubic inch. 

 The camphor weighed 11*4 grains, but some minute crystals 

 of it were observed at the top of the tube, so that the loss of 

 weight was greater than that due to voltaic action. 



(44.) The smallness of the quantity of the gas which had 

 been added to the nitrogen precluded an accurate analysis of 

 it ; enough was ascertained, however, to lead me to believe 

 that it was hydrocarbonous, and it then became my aim to 

 produce it in greater quantities. I attached a piece of cam- 

 phor to a platinum wire, and to the same wire I also attached 

 a piece of sponge platinum ; I passed these up into a tube of 

 nitrogen over distilled water, and at the expiration of three 

 months the gas had increased O'l cubic inch ; this proved 

 that the camphor vapour was decomposable by the catalytic 

 action of platinum at ordinary temperatures, and that the 

 effect in the nitrogen cell of the 

 battery was not due to its voltaic 

 association ; but the experiment 

 did not give me a sufficient quan- 

 tity of the gas for analysis. 



(45.) I therefore had recourse 

 to the apparatus, fig. 3. a is an in- 

 verted cylindrical test-glass ; b a /jr 

 platinum capsule with a pin-hole 

 in the bottom for drainage, stand- 

 ing on an ivory pedestal ; c, c two 

 very stout platinum wires ; d a coil 



of fine platinum wire. Into the capsule b was placed the cam- 

 phor, the glass a filled with distilled water was inverted over 



