PEOFESSOE KOPP ON THE SPECIFIC HEAT OF SOLID BODIES. 
135 
Chloride of Chromium, €r 2 Cl 6 . Violet insoluble chloride of chromium twice boiled 
out with water, washed and dried at 130°. As a porous mass this substance is but ill 
suited for an accurate determination of the specific heat. I pressed it, by means of a glass 
rod, in a glass tube into small disks, between which the naphtha could circulate. Th e 
object of this is to prevent a stagnation of the liquid absorbed by the solid mass, in 
consequence of which the water of the calorimeter assumes its maximum more slowdy, 
and hence the specific heat is found too low (compare §§ 18 & 24) ; but this object is not 
quite attained in this way*. 
Experiments with Naphtha A. Glass 1. Temperature of the Air ll 0 -4-ll°-5. 
T. 
T'. 
t'. 
t. 
M. 
m. 
/• y- 
X. 
sp. H. 
O 
O 
o 
o 
grms. 
grms. 
grms. 
grm. 
47-5 
13-2 
12-86 
10-32 
26-93 
3-165 
2-095 0-431 
0-651 
0-139 
47-5 
13-0 
12-73 
10-13 
26-97 
55 
55 55 
„ 
0-151 
43-8 
12-9 
12-63 
10-33 
26-945 
55 
55 55 
55 
0-143 
46-0 
13-0 
12-65 
10-21 
26-94 
55 
2-085f „ 
55 
0-140 
Mean . . . 0T43 
I should have liked to determine the specific heat of a solid metallic chloride of the 
formula 11 Cl 3 , and tried with chloride of antimony, but it coloured naphtha yellow 
when poured upon it, and became itself milky white, forming a heavy layer below the 
naphtha, and fused completely a little above 40°. 
53. Chloride of Zinc and Chloride of Potassium, ZnK 2 Cl 4 . Crystals dried at 100° 
to 110°$. 
Experiments with Naphtha A. Glass 1. Temperature of the Air 14°-3-14°-5. 
T. 
T'. 
i. 
t. 
M. 
in. 
/• 
y- 
X. 
sp. H. 
o 
o 
o 
0 
grms. 
grms. 
grms. 
grm. 
48-7 
16-2 
15-93 
13-53 
26-915 
3-01 
2-02 
0-431 
0-651 
0-155 
47-1 
16-3 
16-04 
13-77 
26-965 
55 
,, 
55 
55 
0-155 
46-5 
16-4 
16-12 
13-92 
26-955 
55 
„ 
55 
0-150 
44-1 
16-4 
16-14 
14-13 
26-94 
55 
2-00f 
55 
„ 
0-147 
Mean . . . 0T52 
* The above source of error was of more importance, and the experiments gave far lower numbers for the 
specific heat of chloride of chromium when this body was not formed in disks, but just placed in the vessel and 
moderately lightly pressed. The following results were obtained in this manner : — 
Experiments with Naphtha A. Glass 2. Temperature of the Air ll°-5. 
T. 
T'. 
t'. 
t. 
M. 
m. 
/• 
y- 
X . 
sp. H. 
46-4 
O . 
13-4 
13-12 
10-52 
grms. 
26-915 
grms. 
2-425 
grms, 
3-035 
0-431 
grm. 
0-487 
0-134 
45-6 
13-8 
13-53 
11-04 
26-985 
„ 
„ 
0-131 
45-7 
13-8 
13-52 
11-02 
26-99 
yy 
yy 
0-132 
45-6 
13-8 
13-48 
11-02 
26-95 
„ 
3-015f 
yy 
0-123 
f After drying the stopper. 
+ “ These crystals were deposited from a solution which contained for one equivalent of chloride of potassium 
MDCCCLXV. U 
