PROFESSOR KOPP ON THE SPECIFIC HEAT OF SOLID BODIES. 
113 
37. Silicium . — I have investigated this substance in four different modifications. 
Amorphous Silicium *. — For the experiments picked coherent pieces were used, which 
had stood for several days in vacuo over sulphuric acid. 
Experiments with Naphtha A. Glass 3. Temperature of the Air 19°-2. 
T. 
T'. 
t'. 
t. 
M. 
m. 
/• 
V' 
X. 
sp. H. 
0 
grms. 
grm. 
grms. 
grm. 
0-251 
5l-5 
20-7 
20-38 
18-13 
26-95 
1-095 
2-88 
0-431 
0-453 
50-0 
20-8 
20-54 
18-46 
26-975 
55 
„ 
99 
99 
0-208 
50-4 
21-0 
20-66 
18-55 
26-98 
„ 
,, 
99 
99 
0-221 
50-5 
20-9 
20-59 
18-52 
26-935 
„ 
2-87f 
„ 
99 
0-177 
Mean . . . 0-214 
The very discordant results of these experiments are very little trustworthy ; the 
quantity of silicium, 1 grm., was too small, and its thermal action inconsiderable as com- 
pared with that of the other substances immersed with it in the water of the calorimeter. 
Graphitoidal Silicium J. 
Experiments with Naphtha A. Glass 3. Temperature of the Air 16°-7-17°-2. 
T. 
T'. 
a. 
t. 
M. 
m. 
/• 
y- 
x. sp. H. 
O 
o 
o 
o 
grms. 
grms. 
grm. 
grm. 
51-0 
18-8 
18-51 
16-34 
26-965 
3-155 
1-83 
0-431 
0-453 0-182 
52-3 
19-1 
18-82 
16-59 
26-975 
99 
99 
99 
„ 0-181 
51-1 
18-9 
18-62 
16-44 
26-98 
99 
99 
99 
„ 0-185 
50-4 
18-8 
18-52 
16-43 
26-95 
l-81f 
99 
„ 0-174 
Mean . . . 0-181 
Crystallized Silicium . — Grey needles §. 
Experiments with Naphtha A. Glass 1. Temperature of the Air 19°-1. 
T. 
O 
T'. 
o 
t'. 
0 
t. 
o 
M. 
grms. 
m. 
grms. 
/• 
grm. 
y- 
X. 
grm. 
sp. H. 
53-8 
21-1 
20-83 
18-53 
26-94 
2-395 
1-955 
0-431 
0-651 
0-168 
52-6 
21-0 
20-74 
18-52 
26-975 
99 
99 
99 
, 5 
0-168 
52-3 
21-0 
20-72 
18-52 
26-98 
99 
99 
99 
55 
0-168 
51-9 
21-0 
20-66 
18-53 
26-975 
99 
l-935f 
Mean 
55 
0-156 
0-165 
* “ Prepared from silicofluoride of potassium by means of sodium.” — Wohler. 
t After drying the stopper. 
+ “ Obtained by melting silicofluoride of potassium, or sodium, with aluminium ; the aluminium was then 
extracted with hot hydrochloric acid, and the oxide of silicium with fluoric acid.” — Wohler. 
§ “ This silicium was prepared from the silicofluoride of potassium, or sodium, by sodium and zinc, and the 
lead (from the zinc) removed by nitric acid. Whether it was afterwards treated with hydrofluoric acid 1 
cannot say, but probably so. It was quite unchanged when heated in the vapour of hydrochlorate of chloride 
of silicium (passed by means of hydrogen). Probably it contained, however, like all silicium reduced by zinc, 
a trace of iron, which appears when it is heated in chlorine. An experiment with another portion of such 
silicium gave, however, so little iron that its quantity could not be determined.” — Wohler. 
R 
