on Electric Discharges through Water. 149 
and one-ninth of an inch in diameter, as was left on passing 
the electric spark through the gaz, afforded by the third or 
fourth experiment. 
Hence it seems, that water is decompounded by the electric 
discharge, before the whole of the common or atmospherical 
air is detached from the water, by merely the impulse of each 
discharge. Yet I think it probable that, after the discharges 
have been passed through the same water for a certain time, 
the whole of the air contained in water will be expelled, and 
no gaz be produced, but that compounded by means of the 
electric fire from water ; in which case, supposing the gaz so 
produced to be at last merely hydrogen and oxygen gaz, it will 
totally disappear on passing through it an electric spark. But 
I have never been able to determine this point; because the 
tubes were always broken after obtaining a few products, or 
long before it could reasonably be supposed the whole of the 
air of the water was expelled from it. 
H. To the gaz obtained in the experiment E was added, 
over water, an equal bulk of almost pure nitrous gaz. Fumes 
of nitrous acid appeared, and the gaz examined was reduced 
almost one-third of its bulk. A small bubble more of nitrous 
gaz being let up no further diminution took place. To this re- 
sidue was added half its bulk of oxygen gaz, obtained from 
oxymuriate of potash. This mixture of gazes having stood 
several days over well burnt lime and boiled quicksilver, an 
electric spark was passed through the mixture, over quick- 
silver ; by which its bulk was instantly diminished one-fourth.. 
But no moisture could be perceived upon the sides of the tube, 
or on the quicksilver. The failure of the appearance of mois- 
ture was imputed to a bit of lime accidentally left in the tube* 
