PEOFESSOE B. C. BEODIE ON THE ATOMIC WEIGHT OF GEAPHITE. 
257 
The following are the results of the analysis of the bodies : 
Substance taken. Carbonic acid formed. 
Water formed. 
1. Expt. I. . 
. . . 0-367 
1-1051 
0-0163 
2. The same 
. . . 0-3783 
1-1366 
0-0139 
3. Expt. II. 
. . . 0-3979 
1-1938 
0-0158 
4. The same 
. . . 0-3927 
1-1724 
0-0155 
numbers give the following per-centage composition : — 
1 . 
2 . 
3. 
4. 
Carbon 
. 82-12 
81-95 
81-80 
81-41 
Hydrogen 
0-49 
0-41 
0-44 
0-43 
Oxygen 
. 17-39 
17-64 
17-76 
18-16 
100-00 
100-00 
100-00 
100-00 
The substance derived from the preceding body, by the elimination of 1 atom of 
water from 3 atoms of the substance, would have the formula Ce 6 H 4 0i,. 3 (C 22 H 2 04 ) 
= Cgg H4 O4 + H2 0. 
The calculated composition of this body is as follows : — 
Cee • 
. 792 
81-48 
H 4 . 
4 
0-41 
0 „ . 
. 176 
18-11 
972 
100-00 
Every 100 parts of the substance taken would leave a residue of 98T8 parts, and the 
water formed would amount to 1-80 part. The amount of carbonic oxide formed in 
the preceding experiments is so small, that it can hardly be regarded as an integral part 
of the decomposition ; and if this amount be added to the residue, we arrive at precisely 
the theoretical numbers. 
By a greater elevation of temperature the substance undergoes further change, with 
the loss of carbonic acid and carbonic oxide. But it may be exposed to a red heat for 
several hours in a current of nitrogen and only undergo a very partial decomposition, the 
residual substance containing a considerable portion both of hydrogen and oxygen. 
Buff and Wohlee, in their researches “ On the Graphitoidal Form of Silicon*,” dis- 
covered a remarkable series of compounds derived from it. When hydrochloric acid gas 
is led over this form of silicon at a low red heat, a volatile liquid is formed containing 
silicon, chlorine, and hydrogen, to which they assign the formula Si 2 H 2 CI3. With 
hydriodic acid gas a similar reaction takes place, with the formation of the corre- 
sponding compound Si 2 H 2 13 . In water, these substances decompose with the produc- 
tion of a compound of silicon, hydrogen, and oxygen, of the formula Si 4 H 4 O 5 . The 
analyses are unfortunately neither so concordant nor so exact as might be desired ; but 
the formulae are derived from the consideration of a system of decompositions, which 
* Liebig’s ‘ Annalen,’ vol. civ. p. 94. 
