164 
PROFESSOR KOPP ON THE SPECIFIC HEAT OF SOLID BODIES. 
Experiments with Naphtha B. Glass 1. Temperature of the Air 18 o, 0-18°-4. 
T. 
T'. 
t'. 
t. 
M. 
m. 
/• 
y- 
x. 
sp. H. 
O 
o 
o 
0 
grms. 
grms. 
grm. 
grm. 
51-4 
20-1 
19-82 
17-24 
26-97 
2-475 
1-77 
0-419 
0-651 
0-336 
50-9 
20-0 
19-74 
17-20 
26-99 
55 
55 
55 
55 
0-334 
51-6 
20-1 
19-78 
17-15 
26-975 
55 
55 
55 
0-345 
50-9 
20-1 
19-77 
17-20 
26-96 
55 
1-75* 
55 
55 
0-357 
Mean . . . 0-342 
The pieces of amorphous sugar used for these experiments were clear even when the 
experiments were concluded. In the investigation of such a hygroscopic substance it is 
impossible to avoid with certainty any absorption of water ; yet it seems to me improbable 
that the difference between the number O' 342 found for amorphous cane-sugar between 
20° and 51°, and 0'301 for crystallized sugar between the same limits, depends on an 
absorption of water by the former ; but it is probable that the greater specific heat 
found for amorphous sugar depends on the fact that at 50° even it contains some heat 
of softening. According to Wohler’s observations, bodies in the amorphous condi- 
tion have other, in general lower, fusing-points than those in the crystallized statef; 
crystallized cane-sugar melts at 160° C., amorphous between 90° and 100 p ; at the latter 
temperature the amorphous sugar may be drawn out in threads, but even at a lower tem- 
perature the softening begins. 
Mannite , € 6 H 14 G 6 . Crystallized mannite, dried at 100°, was melted in the oil-bath 
at 160°-170°, and the radiant crystalline mass was comminuted. It gave the following 
results J. 
Experiments with Naphtha B. Glass 3. Temperature of the Air 17°T-17°'8. 
T. 
T'. 
t'. 
t. 
M. 
m. 
/• 
y- 
X. 
sp. H. 
o 
O 
o 
o 
grms. 
grms. 
grm. 
grm. 
51-1 
19-3 
18-92 
16-57 
26-98 
2-56 
1-815 
0-419 
0-453 
0-318 
51-6 
19^4 
19-12 
16-64 
26-93 
55 
„ 
55 
55 
0-336 
51-0 
19-5 
19-19 
16-82 
26-965 
55 
55 
55 
0-319 
51-3 
19-6 
19-31 
16-92 
26-93 
55 
1-805 
* 
55 
55 
0-321 
Mean 
0-324 
After dryin 
g the 
stopper. 
t Ann. 
der Chem. und Pharm. vol. xli. p. 155. 
I also worked with mannite which was 
crystallized i 
in slender prisms and dried at 100°. 
Experiments with Naphtha B. Glass 
3. Temperature of the Air 17°-4. 
T. 
T'. 
t. 
M. 
m 
/- 
y 
X. 
sp. H. 
O 
O 
0 
0 
grms. 
grms. 
grms. 
gras. 
49-5 
19-2 
18-85 
16-61 
26-95 
2-13 
2-14 
0-419 
0-453 
0-302 
51-3 
19-3 
19-03 
16-64 
26-94 
„ 
„ 
0-311 
50-5 
19-3 
19-04 
16-74 
26-98- 
,, 
2- 13* 
99 
0-302 
I consider the somewhat larger numbers obtained by using the compact pieces which had been melted to be 
more correct. 
