Silliman and Wurtz on Flame Temperatures. 348 
of water into steam being 537°; to get the actual temperature 
of a oxyhydrogen flame, we must modify the above equation, 
so that 
po 4462'—(9 x 587") _ 951° GC. = 12364° F.; 
£3945 ; 
which is the temperature actually possible in the flame of the 
compound blow-pipe, were the combustion instantaneous and 
complete. 
When hydrogen gas burns zn air, however, as has been 
before stated, another deduction of enormous amount must be 
made from the above figures, due to the heat required to expand 
the nitrogen. This is obtained simply by adding to the divisor, 
as above, the weight of the nitrogen of the air employed, mul- 
tiplied by its specific heat. The weight of the nitrogen in air= 
3318 times the oxygen; so that the latter of the above equa- 
tions becomes 
i 34462° —(9 x 537°) pelle ae are PE 5 
ding = 2744°5° C.=4972° F. 
43245 +(8x38-318 x 0:2438) ee 
We have here a full explanation of the extraordinary loss of 
wer in illuminating gas by admixture of air, which we 
ave discussed elsewhere.* The nitrogen of such air is not 
merely a diluent, or even a mere deductive quantity ; its specific 
heat is an actual divisory fanction in diminishing the flame-tem- 
ors ; 
expression is changed by simply omitting the subtrahend in 
the numerator: 
=3192° C. = 5778° F. 
mE 
43245464714 
8. Calculation of the calorific effect of carbonic oayd burning in 
air.— As the product of combustion is here solely carbonic acid, 
no latent heat of steam enters, and the calor 
18 the same, under all circumstances, 1m alr. In the numerator 
We substitute of course the calorific equivalent of one volume 
of carbonic oxyd from Table I; and in the denominator, for 
the specific heat of 9 Ibs. of water, that of 22 Ibs. of carbonic 
acid, being the weight of the latter formed ay the combustion 
and combination of 14 Ibs. of carbonic oxyd, with 8 Ibs. of 
* This Journal, II, xlviii, 40. 
