On some Chevucal Agencies of Electricity . 11 



having the properties of niirous acid was not produced, and 

 the lor.2,er the operation the greater was the quantity that 

 appeared. 



Volatile alkali likewise seemed to be always formed in 

 very minute portions, during the first few minutes, in the 

 purified water in the gold cones, but the limit to its quantity 

 was soon attained. 



It was natural to account for both these appearances from 

 the combination of nascent oxygen and hydrogen respec- 

 tively, with the nitrogen of the common air dissolved in the 

 water; and Dr. Priestley's experiments on the absorption of 

 gases by water (on this idea) would furnish an easy explana- 

 tion of the causes of the constant production of the acid, and 

 the limited production of the alkali : for hydrogen, during 

 its solution in water, seems to expel nitrogen; whilst nitro- 

 gen and oxygen are capable of co-existing dissolved in that 

 fluid *. 



To render the investigation more complete, I introduced 

 the two cones of gold with purified water under the receiver 

 of an air pump ; the receiver was exhausted til! it contained 

 only l-64lh of the orignal quantity of air; and then, by 

 means of a convenient apparatus, the tubes were connected 

 with an active Voltaic pile of fifty pairs of plates of four 

 inches square. The process was carrie<l on for IS hours, 

 when the result was examined. The water in the neoative 

 tube produced no effect upon prepared litmus, but rhat ia 

 the positive tube gave it a barely perceptible tinge of red. 



An incomparably greater quantity of acid would have 

 been formed.ui a siiTular time in the atmosphere, and the 

 .small portion of nitrogen gas remaining in contact with the 

 water seemed adequate to the efTect. 



T repeated the experiment under more conclusive circum- 

 stances. I arranged the apparatus as before; I exhausted 

 the receiver, and filled it wilh hydrogen gas from a conve- 

 nient airholdcr; I made a second exhaustion, and again in- 

 troduced hydrogen that had been carefully prepared. The 

 process was conducted for 24 hours, and at the end of this 



* Priestley'* Kxpcrimcnts and Observations, vol. i. p. 5r>. 



time 



