258 PEOfESSOE B. C. BEODIE ON THE ATOMIC WEIGHT OP GEAPHITE. 
hardly leaves room for any other hypothesis. The general properties of the subsmce 
Si HO correspond very closely with those of the graphite compound as separated from 
Us!ombin Xs by an Lid. It is described as a white and voluminorrs body wMch 
floats upon water, in which it is very sUghtly soluble. Heated to a temperate of above 
300“ iUs decomposed with ignition and evolution of hydi'ogen. The ratio of the num er 
!f eialents of hydrogen to those of oxygen is as 4 to 5. It is formed exclr^ively from 
graphitoidal silicon, as the graphite compound from graphitoidal 
conriderations we may infer that the graphite compound is the same teim m the sys 
o™ rb n as the silicL compound in the system of sUicon. men we proceed to s ra 
^rinalogy in the formula of the substance, we are led to very remai-kable con- 
“'tC total weight of graphite, which in this compound ^ ^ 
ofhydrogenand the 5 of oxygen, is 132. If we assume that this weight is, like the ^ 
spending weight, 84 of siUcon, to be divided into 4 parts, we arnve at the number oo as 
rlL weight of graphite. Kepresenting this weight by the letters Gr. the formula 
of the substances C„ H, O, and C... H, O., and C„ H, O,., become 
Gr, H.O, 
Gi'g H 2 O 4 
Gr24H4 0ii- 
We are acquainted with a property of graphite by which tins 
According to the law of DnWKG and Petit, which has been confirmed '’I ‘ - 
researches of Regnauet, the specific heats of the elemental bodies laiy inieise) w 
Te^c weights. With L atomic weights of the 
received the elements ai-e divided into two classes, the one in which the pioduct of 
speX ieat into the atomic weight is approximately S-3. the other in which this pro- 
duct is approximately 6 - 6 . This law expresses the only common physical 
which these weights are characterized. To this law, however, there 
exception, namely, the specific heat of carbon in its various forms. The foUowm, are 
the specific heats of carbon as determined by Kegnault 
Specific heats. 
Diamond 
Native graphite 
Graphite from the blast furnace . • 0-19702 
Carbon from gas retorts 0-20o6 
Carbon from anthracite . . • • 
Wood charcoal 
Animal charcoal 
In no single case, whether the atomic weight of carbon be assumed as 6 or as 1.^ 
does carbon confoi-m to the law. The product of the ^P^cific heat of 
atomic weight is with the weight 6 , 1'2, with the Height 1-, - . , 
0-201 
0-2415 
0-26085 
