598 DB. A. DUPEE AND E. J. M. PAGE ON THE SPECIFIC HEAT AND OTHEE 
At first the authors were inclined to attribute the high specific heat observed in the 
weaker spirits to evaporation, which, if it took place to any extent, would, of course, 
make the specific heat appear higher than it really is. 
To test this point, they undertook some experiments in which the weight of the calo- 
rimeter with its liquid contents was carefully taken before and after the experiments, so 
that if any loss took place by evaporation it might become apparent. The following 
results were obtained. 
First, with distilled water, twelve minutes intervened between the first weighing of the 
calorimeter before the experiment and the second weighing after the experiment. 
First experiment, loss observed during the experiment . . 0T6 grm. 
Second experiment, loss observed during the experiment . . 0T25 grm. 
On allowing the calorimeter to stand exposed to the air for twelve minutes, a loss of 
0T7 grm. in the first case, and 0T2 grm. in the second, took place, due to spontaneous 
evaporation. Thus the loss which could fairly be ascribed to evaporation produced by 
the introduction of the heated weight is quite inappreciable. Two similar experiments, 
made with 10 per cent, spirit, gave respectively 0-25 grm. and 0-20 grm. loss in the 
twelve minutes during which the experiment was made, and a loss of 0-21 and 0-21 grm. 
during the twelve succeeding minutes, when the calorimeter was allowed to stand ex- 
posed to the air, showing an evaporation of 0 '04 grm and 0-00 grm. respectively, due to 
the introduction of the heated weight, a quantity which will not account for one-tenth 
of the effect observed. 
Four experiments were then made in which the copper ring, instead of being heated 
to about 97° C., was heated to about 42° C. ; the results are given in the following Table. 
Table IV. 
Copper ring , weight 614-49 grms. 
Copper value of calorimeter and immersed part of thermometer 69-12 grms. 
Quantity of liquid contained in the calorimeter 420*69 cub. centims. 
Time occupied in each experiment 1-5 minute. 
a. Distilled Water. 
Experiment. 
r. t. 
t. | t\ 
V. 
* 
N. 
58. 
14*0 41-64 
12-925 1 16-246 
0-025 
3-342 
7-485 
59. 
14-7 41-94 
12-957 16-335 
0-020 
3-398 
7*422 
Mean value of N 7 - 453. 
1. Spirit 10 per cent. Sp. gravity 0-9814. 
Experiment. 
t". 
T. 
t. 
t'. 
t. 
e. 
N. 
60. 
61. 
14-00 
13-25 
43-00 
41-81 
13-449 
12-339 
16-832 
15-693 
0-025 
0-020 
3-408 
3-374 
7-708 
7-771 
Mean value of N 7*7 39. 
Specific heat of 10 per cent, spirit 103-83. 
