VOLTAIC ACTION OF PHOSPHORUS, SULPHUR AND HYDROCARBONS. 359 



(48.) Alcohol and ether were tried in a similar manner, and produced notable 

 voltaic effects ; alcohol the most powerful probably, on account of its greater solu- 

 bility in water. 



(49.) The rationale of the action in experiments (43.) and (47.) is curious. It 

 seems that the platinum in the nitrogen tube first decomposes the vapour of the hydro- 

 carbons*, and then the same platinum, with its associated plate, recombines the 

 separated constituents with oxygen. In experiment (43.) the decomposition takes 

 place more quickly than the recomposition, as indeed would be expected from the 

 absence of the resistance of the electrolyte in the former case, and hence the increase 

 of gas in the nitrogen tube. 



(50.) The analogy of the action of the above volatile substances strengthens the 

 position advanced (38.), that solid phosphorus should be regarded as volatile at 

 ordinary temperatures, and sulphur when fused ; the whole of these experiments 

 also serve to introduce the galvanometer as a new and delicate test, and in some 

 cases a measurer of volatilization. 



(51.) As the gas battery was shown in the former paper, which I had the honour 

 to communicate to the Society, to give us the power of introducing gases which had 

 been previously untried as voltaic excitants, and to ascertain their electro-chemical 

 relations, it has, by the means detailed in this paper, opened a field for ascertaining 

 the voltaic relations and quantitative electro-chemical combinations of solid and 

 liquid substances, which from their physical characteristics had not hitherto been 

 recognised in lists of the voltaic relations of diff'erent substances, and consequently 

 formed to a certain extent a blank in the chemical theory (may we not now call it 

 law ?) of the voltaic pile. These results, coupled with the previously-arranged tables 

 of electro-chemical relations, and with the great improvements in apparatus for 

 measuring these relations recently made by Mr. Wheatstone and others, offer every 

 promise of the ultimate establishment of accurate measures of affinity. I give the 

 following tables as an approximative list, without attempting to give the degrees of 

 intensity, which can only be filled up by a careful series of reseaiches exclusively 

 devoted to this object. 



(52.) Chlorine. 

 Bromine. 

 Iodine. 

 Peroxides, 

 Oxygen. 



Deutoxide of nitrogen. 

 Carbonic acid. 

 Nitrogen. 



Metals which do not decompose water 

 under ordinary circumstances. 



♦ I use this word here and in the title to avoid periphrasis ; it is not quite correct as applied to some of 

 thjese bodies. 



MDCCCXLV. 3 B 



Camphor. 



Essential oils. 



defiant gas. 



Ether. 



Alcohol. 



Sulphur. 



Phosphorus. 



Carbonic oxide. 



Hydrogen. 



Metals which decompose water. 



