©N tOME CHEltflCAC AGENCIES OF ISEKCTRlCllf'i?, 3g^ 



•* quarter of an hour, the negatiTelj electrified 'tnT)e did iiot Changes pro^ 

 <;hange the colour of turmeric. I introduced into the top fVx^^ .^^ ^^^ 

 of it a bit of glass ; in a few minutes the fluid at th« surface 

 rendered the tint of the paper of a deep bright brown, 



I had never made any experiments, hi which acid matter 

 having the properties of nitrous acid was not produced, and 

 the longer the operation the greater was the quantity that 

 appeared. 



Volatile alkali likewise seemed to be always formed iii 

 T«ry minute portions, during the fir&t few minutes in the pu^ 

 >ified 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 nasceiit oxigen' and hidrogen 

 respectively; with the nitrogen of the common air dissolved 

 in the water: and Dr. Priestley's experiments on the ab- 

 sorption of gasses by water (on this idea) would furnisli an 

 «asy explanation of the causes of the constant production of 

 the acid, and the limited production of the alkali; for hi- 

 drogen, during its solution in water, seems to expel nitro- 

 gen; whilst nitrogen and oxigen are capable of coexisting 

 dissolved in that fluid *. 



To render the investigation more complete, I introduced 

 tlie two cones of gold with purified water under the receiver 

 of an air pump ; the receiver was exhausted till it contained 

 only -j^ of the original quantity of air; and then, bymeanj; 

 of a convenient apparatus, the tubes were connected with 

 an active Voltaic pile of 50 pairs of plates of foiir inches 

 square. The process was carried on for 18 hours, when 

 (he result was examined. The water in the negative tube 

 produced no eficct upon prepared litmus, but that in the 

 positive tube gave it a barely perceptible tinge of red. 



An incomparably greater quantity of acid would have 

 been formed in a similar time in the atmosphere, and the small 

 portion of nitrogen gas remainiing in contact with the water 

 seemed adequate to the effect. 



I repeated the experiment under more conclusive circum- 

 stances. I arranged the apparatus as before ; I exhausted 



* Priestley's Experiments and Observations, Vol. I, p. 59. 



tht 



