358 MR. GROVE ON THE GAS VOLTAIC BATTERY. 



(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 camphor 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 quantity of the gas for analysis. 



(45.) I therefore had recourse to the apparatus, fig. 3. a is an inverted cylindrical 

 test-glass ; h a platinum capsule with a pin-hole in the bottom for drainage, standing 

 on an ivory pedestal ; c, c two very stout platinum wires ; d a coil of fine platinum 

 wire. Into the capsule h was placed the camphor, the glass a filled with distilled 

 water was inverted over it and charged with pure nitrogen, to a level marked some- 

 where below the capsule ; the wires w w' are now connected with a voltaic battery of 

 sufficient power fully to ignite the wire d. 



(46.) After the wire was ignited the volume of the gas gradually increased ; when 

 the original volume was doubled, the gas was examined. It had a strong disagree- 

 able odour, very similar to that of coal-gas ; it burned with a blue flame, slightly 

 tinged with yellow: placed in an eudiometer, such as I formerly described*, and 

 mixed with hydrogen, it underwent no alteration. Two volumes of it, mixed with 

 one volume of oxygen, contracted one-sixth of the whole volume, and subsequently 

 agitated with lime-water, contracted two-sixths more, lining the tube with a crust of 

 carbonate of lime. The residual gas was nitrogen. It was thus clear that the vapour 

 of camphor was decomposed by the ignited wire into carburetted hydrogen and 

 carbonic oxide, and the analogy is too direct to leave any doubt that these gases 

 were also formed in experiments (43.) and (44.) by the influence of the platinum foil 

 and spongy platinum. 



The apparatus (fig. 4) offers a most convenient means of decomposing volatile 

 hydrocarbons, and possibly other substances. 



(47.) Portions of oil of Turpentine and of Cassia were now placed in capsules (fig. I), 

 weighed and exposed each to an atmosphere of nitrogen in the large tube of a gas 

 battery, by the same means as described (42.) ; they gave a very decided deflection 

 (the nitrogen representing zinc). This deflection continues, and the liquid is slowly 

 rising in the oxygen tubes, but the rise is too slight at the time of my writing this 

 paper to derive any useful result from examining the present weight-J-. 



* Philosophical Magazine, August 1841, p. 99, and Philosophical Transactions, 1843, p. 105. 



t Dec. 1845.— The rise of liquid has been slow but continuous, and the galvanometer feebly deflected. In 

 the Turpentine experiment the rise is =0-7 cubic inch, in the Cassia 0-5 ; the weights, however, from the irregu- 

 larity of absorption and evaporation, give no data as to the equivalent consumption ; thus the Turpentine has 

 lost 0-7 grain, the Cassia gained 005 grain. 



