OF GASES AND VAPOURS. 209 
pour under the pressure of one atmosphere, referred to the unit 
of weight = 0°09248. 
Referred to the same volume at the boiling-point of mercury, 
this specific heat is compared with that of atmospheric air, 
6°9785 x 0°09248 
0°267 
The difference of the specific heats, pressure and volume 
= 2°04. 
being constant, is £4 _ 01999; consequently the specific heat 
with constant volume referred to the unit of weight=0-:07249, 
and the relation of both=1:275. 
28. From the observations of Marx, I find the boiling-point of 
the sulphuret of carbon with a pressure of 0™76=336°905 Paris 
lines=37°83 R. If the temperatures are reckoned from this 
point, I obtain the formula 
Ja alll af BLL 
logs 26B8 48" a, xeae ple GEOe) 
r t Observed 
in Pans [2 = Sd Difference: par are 
lines. Calculated. Observed. from 0°. 
32:00 | —47-92 | — 44-83 | +3:09 - 7 
58°50 | —37:34 | —37:83 | —0-49 0 
96°92 | —27-74 | —27-83 | —0:09 10 
156:25 | —17-78 | —17-°83 | —0-05 20 
24313 | — 7°84 | — 7:83 | +0-01 30 
367°62 |+ 2-18 | + 2:17 | —0-01 40 
494:00 | + 9:83 |+ 9-67 | —0-16 475 
The coincidence is, with the exception of the two first values, 
certainly greater than the errors of the observations themselves. 
The observed heights of the mercurial columns are not reduced 
to one temperature, on which account this expression has less 
value than the previous ones. I therefore pass over further cal- 
culations from the formula; it is for centigrade degrees, 
p _ 47126 .t 
RE pis REG 
in which the temperatures must then be counted from 47°27 C. 
29. Bunsen * has published an account of the elastic forces 
calculated by him from experiments of sulphurous acid. They 
* Poggendorff’s Annalen, xlvi. 97. 
