100 
PROFESSOR KOPP ON THE SPECIFIC HEAT OF SOLID BODIES. 
II. — Experiments with Glass 2. Temperature of the Air 12°T-12°-7. 
T. 
T'. 
t' 
t. 
M. 
/• 
x. 
sp. H. 
49-0 
13-8 
13-53 
11-02 
grms. 
26-955 
grms. 
3-28 
grm. 
0-487 
0-438 
45-9 
14-1 
13-83 
11-50 
26-93 
3-48* 
55 
0-427 
43-3 
14-2 
13-86 
11-73 
26-95 
55 
0-427 
46-6 
14-5 
14-23 
11-85 
26-95 
3-475 f 
5 5 
0-435 
Mean 
0-432 
III . — Experiments 
with Glass 
1. Temperature of the Air 16° 
•7. 
T. 
T'. 
t'. 
t. 
M. 
/• 
so. 
sp. H. 
51°-4 
18-6 
18*32 
16-02 
grms. 
26-98 
grms. 
2-895 
grm. 
0-651 
0-429 
51-5 
18-4 
18-06 
15-73 
26-97 
„ 
55 
0-431 
51-5 
18-4 
18-14 
15-81 
26-985 
„ 
55 
0-431 
51-0 
18-5 
18-22 
15-93 
26-96 
2-88f 
55 
0-434 
Mean 
0-431 
IV . — Experiments 
with Glass 
3. Temperature of the Air 16° 
•7. 
T. 
T'. 
t'. 
t. 
M. 
/• 
X. 
sp. H. 
0 
51-7 
18-7 
18-43 
16-22 
grms. 
26-935 
grms. 
3-195 
grm. 
0-453 
0-423 
50-7 
18-6 
18-32 
16-14 
26-935 
55 
„ 
0-431 
50-7 
18-6 
18-27 
16-13 
26-95 
55 
55 
0-421 
50-2 
18-6 
18-26 
16-14 
26-93 
3-18 f 
55 
0-426 
Mean 
0-425 
The average of the means of these four series of experiments, 0-436, 0-432, 0-431, 
0-425, gives 0-431 as the specific heat of the coal-tar naphtha A between 14° and 52°; 
this value is taken in calculating the experiments in the following section. 
28. If it were only a question as to the determination of the specific heat of this 
naphtha, the method described in the preceding might be advantageously replaced by 
another. For by this method the specific heat of the liquid must be found somewhat 
too great, owing to the fact that in the empty space in the glass under the stopper a dis- 
tinct quantity of vapour is formed, which condenses when the glass is dipped in the 
water of the calorimeter (compare § 25). Direct experiments J, in which this forma- 
tion of vapour was almost entirely avoided, have shown that the method used for the 
previous determinations, that is, the use of glasses for heating the liquid in which a 
* After adding some naphtha. t After drying the stopper. 
J I determined the specific heat of coal-tar naphtha A, using a glass in which only very little vapour could 
form above the heated liquid. This glass (which I used in experiments for the determination of the specific 
heat of liquid compounds) had a narrow neck, and was filled so that there was very little space in which 
vapour could form; the calorimetric value of this glass, in so far as it was immersed in the water of the 
