602 DE. A. DUPRE AND F. J. M. PAGE ON THE SPECIFIC HEAT AND OTHEE 
heat of all is below that of water. In fact the specific heat obtained by him for mix- 
tures, up to an alcoholic strength of 60 per cent., is below that obtained in the present 
series of experiments, whilst for all stronger mixtures and absolute alcohol his results 
are higher. 
Schnidaritsch’s paper, though of some length, does not give the requisite data to 
check the results obtained by him, inasmuch as the correction applied in each case is 
not given. In his statement, however, as to how the corrections were made, there is an 
obvious error, as he uses Regnault’s formula for the amount of cooling observed in his 
(Regnault’s) calorimeter, though his (Schnidaritsch’s) calorimeter is of different shape 
and one-fourth of the size. Any correction thus calculated which Schnidaritsch has 
applied to his experiments will be obviously too small. Moreover Schnidaritsch has 
experimented with but comparatively small quantities, about 10 grms. of spirit enclosed 
in a glass tube, whilst his calorimeter only contained 100 cub. centims. 
Lastly, the thermometer employed to take the temperature of the calorimeter could 
only be read to of a degree, which is rather too large a fraction of the total rise 
observed. 
His method of heating the glass tube and contents seems rather objectionable ; and 
although the same glass tube and the same portion of the mixture, hermetically sealed 
in the glass tube, were used by him throughout the series of experiments on that mixture, 
yet the results obtained do not agree very well; with the 20 per cent, spirit there is a 
difference of nearly 3 per cent. 
The authors nevertheless thought it advisable to repeat some of the experiments on 
the 20 per cent, spirit, estimating its specific heat between the same limits as those used 
by Schnidaritsch. Instead of using a glass tube they employed an annular vessel 
(similar to the one previously described, but smaller and made of thinner brass) to 
enclose the spirit to be heated. This heating was effected in the same apparatus as 
that employed to heat the metallic weights, but the vapour of boiling alcohol was used 
instead of steam. In all other respects the experiments were conducted as usual. 
The results of these experiments are given in Table VI. 
The letters have the same signification as in previous Tables. 
Table VI. 
Amount of water in calorimeter 1155*766 grms. 
Water value of calorimeter and immersed part of thermometer 9*734 grms. 
Water value of annular brass vessel 2*5'97 grms. 
Time occupied in each experiment 2 m 30 s . 
a. Distilled Water; amount taken 32*3475 grms. 
| Experiment, j 
t". T. 
t | t . 
V. 
e. 
Specific heat. 
72. 
17*30 75-5 
16-502 18-220 
0-008 
1-721 
100-55 
