VOLTAIC ACTION OF PHOSPHORUS, ETC. 287 



Cubic in. 



Experiment 2. In oxygen tubes . . . . =O'5 

 Deutoxide of nitrogen . . = 2*5 



Experiment 3. In oxygen tubes .... =O'2 

 Deutoxide of nitrogen . . =075 



In oxygen tubes, rise . . . =0^34 

 Mean result In deutoxide tubeS) rise . . =r5 



The slight excess being undoubtedly due to the greater 

 solubility of the deutoxide, it appears that four volumes of 

 deutoxide of nitrogen are absorbed in the gas battery for one 

 of the associated oxygen, and the result would be a compound 

 of I equiv. nitrogen + 3 oxygen, or hyponitrous acid, which is 

 exactly that formed by the slow combination of these two 

 gases in the ordinary chemical way. The difference of 

 amount of action in the three experiments depended on the 

 temperature, the second experiment being made towards the 

 close of last summer, the last experiment during the con- 

 tinuous cold weather of the present spring. 



These experiments, coupled with the converse ones with 

 hydrogen and deutoxide of nitrogen (30), afford very satis- 

 factory instances of the illustration of the law of definite 

 combining volumes by the gas battery, exhibiting in one 

 result, and itself registering that result, the action of equivalent 

 chemical combination, catalysis and voltaism. 



(32.) I now pass to the experiments which will form the 

 more immediate subject of this paper. The temporary action 

 to which I have alluded (21) being greater when nitrogen and 

 oxygen were the gases used, if the nitrogen were obtained by 

 burning phosphorus in atmospheric air, than if procured from 

 other sources, it naturally occurred to me that this action was 

 due either to some phosphorous acid remaining in a state of 

 vapour in the nitrogen, or to a slight portion of the phosphorus 

 itself being held in solution in the nitrogen, as believed by 

 Vauquelin and the older experimentalists. If this last suppo- 

 sition were the correct one, it seemed to offer a means of 

 rendering phosphorus, though a non-conductor and insoluble 

 in aqueous liquids, yet a permanent voltaic excitant analogous 

 to the oxidable metals. 



(33.) A small piece of phosphorus having been carefully 



