292 EXPERIMENTAL INVESTIGATIONS. 



sumption of deutoxide of nitrogen being exactly the same in 

 both batteries. In another experiment, which I did not re- 

 cord, on account of a minute bubble of air having entered the 

 tubes containing the deutoxide, the phosphorus appeared to 

 have exercised a retarding influence on the voltaic combination 

 of deutoxide of nitrogen and oxygen ; this I attributed to a 

 slight deposit of phosphorous acid upon the platinum, by 

 which its catalytic power was deteriorated. 



(38.) It thus appears that the effect we have been examin- 

 ing, of the diffusion of phosphorus in gas, is not due to any 

 peculiarity of nitrogen, and is not peculiar to any particular 

 gas, as once believed ; but being in all probability common to 

 all gases which do not exercise a specific action on the phos- 

 phorus, it may be more properly called a volatilisation of 

 phosphorus at ordinary temperatures than a solubility in gas ; 

 the ordinary slow combustion of phosphorus in air is, in fact, 

 a combustion of its vapour. I incline to think that the in- 

 feriority of its vaporisation in pure oxygen is due to a pro- 

 tecting film being formed, and that the phenomenon is in 

 some respects analogous to the inactivity of iron in nitric acid. 



(39.) Phosphorus in nitrogen was associated with hydrogen 

 in the gas battery, to ascertain their voltaic relation ; the 

 hydrogen was positive to the phosphorus, i.e. represented the 

 zinc of an ordinary voltaic combination. 



(40 ) To realise the curious novelty of two non-conducting 

 solids forming the elements of a voltaic battery, and producing 

 a continuous current, phosphorus suspended in nitrogen in one 

 tube of a gas battery was associated with iodine in nitrogen 

 in the other ; a very decided current was the result, which 

 continued for months, the nitrogen remaining unaltered in 

 volume, but the liquid becoming gradually tinged by the 

 excess of iodine vapour. The following is the result of the 

 experiment : 



Charged January I, 1845. 



Weight of iodine . . =5 '9 grains. 

 Weight of phosphorus . = 6*4 grains. 



Examined May 17, 1845. 



Weight of iodine . . =4*6 grains. 

 Weight of phosphorus . =6'28 grains. 



