79 On Oil and Oil-gas. 
illumination. The entire gas including the 
carbonic acid, which was about 7 per cent., 
was found by weighing to be of the specific 
gravity ,875. After extracting the carbonic 
atid by lime water (7), the rest (93) took 210 
oxygen and gave 128 carbonic acid by 
Volta’s eud ometer; and there was a remain- 
der of 10 incouibustible, having all the 
inarks of azotic gas. Also 100 measures of 
the entire gas reduced to 93 by lime-water, 
being treated with 40 or 50 measures of oxy= 
fiuriatic acid gas, lost instantly 50 measures, 
as was found by washing out the excess of 
oxymutiatic acid; the remaining 63 were 
not sensibly affected by a second portion 
of oxymuriatic acid for at least 5 minutes in 
full day-light. This residue 63, being fired 
with oxygen, took 89 measures, and yielded 
AG of carbonic acid, with the usual slight va- 
riations in the different experiments ; and a 
remainder of 10 azotic gas. 
Oil-gas I find is not altered by being kept 
2 or 8 years over water or mercury, either 
by itself or in mixture with 3 or 4 times its 
bulk of oxygen gas. 
I have alluded to the absorbability of oil- 
eas by water: Lt may be of some use to give 
the results of one trial. Into a well stoppered 
bottle filled with 2700 grains of rain-water 
