SPECIFIC GRAVITY OF NITROGEN, ETC. 
343 
I.S064, and it consists of one atom or volume of nitrogen and 
one of carbon, condensed into one volume; this gives for the 
specific gravity of carbon vapor .8342. Again, the specific 
gravity of olefiant gas is .9709 by careful experiments made 
by Dr. Thomson; and this gives for carbon vapor .8321; both 
these differ less than the jq\q of an unit from which is 
nearly the mean between them. The same may be shown 
from carbonic acid, carbonic oxide, and other compounds. 
In a former paper I proved that 12 to 1 is much nearer the 
truth than 12i to 1 for the atomic weight of the specific 
gravity of carbon vapor. The accurate experiments of 
Dumas give the specific gravity of chloroform 4.2, and of 
chlorocyanic acid 2.153, and taking carbon and hydrogen 
3JL the former gives 2.4991 and the latter 2.5005 for the 
specific gravity of chlorine; all but identical with the above 
determinations. The vapor of sulphur presents a remarkable 
peculiarity. The specific gravity of sulphuretted hydrogen 
was found by Gay-Lussac to be 1.1921, and by Thomson 
1.1788; the former gives for the specific gravity of sulphur 
vapor 2.2436, and the latter 2.2188; both are nearly, and the 
mean very nearly \°. The specific gravity of sulphurous 
acid is found by Davy 2.229, and by Thomson 2.221; both 
these also give very nearly 2 -g°, which lies between them; 
from these we should conclude that the specific gravity of 
sulphur vapor is \° double that of oxygen. But the specific 
gravity of sulphur vapor is, by the experiments of Dumas, 
between 6.51 and 6.617, and by those of Mitscherlitch, 6.9; 
the mean is very nearly 6 T °, or three times \°. But what if 
sulphur vapor consist of single groups of three atoms each ? 
This would perfectly solve the difficulty; and is there in it 
any thing objectionable, or contrary to analogy ? Etherine 
consists of single groups of six atoms each, and eamphene of 
thirteen atoms in a single group, and there are many other ex- 
amples. This also follows from the fact that sulphur, after 
attaining by increased temperature its highest degree of 
liquidity, does, by increase of temperature, thicken till it be- 
comes a soft solid; and again, at a still higher temperature, 
becomes again liquid, and is by farther heat converted into 
