ON THE THERMAL PROPERTIES OF ALCOHOL. 
135 
16. A set of determinations have been made by Zuk (Z. Rusk. Chim. Obs., 13 (2), 
p. 239) of the volumes of alcohol under the critical pressure observed by Sajotcewsky 
of 62'1 atmospheres ( = 47,196 mms.). We are now in a position to compare our 
results with his. Zuk adopts the specific gravity 0*80614 at 0°, a number close to 
that adopted by us, 0*80625. The comparison is as follows : — 
T. 
V 0 - 
= 1. 
E. and Y. 
Zuk. 
O 
124-3 
1-153 
1-1667 
132-5 
1-170 
1-1828 
140-2 
1-189 
1-2004 
150-6 
1-216 
1-2291 
169-8 
1-274 
1-2914 
181-0 
1-317 
1-3387 
190-5 
1-357 
1-3815 
200-5 
1-406 
1-4398 
211-6 
1-473 
1-5228 
218-5 
1-524 
1-5983 
It is evident that there are considerable differences between the two sets of results. 
These are probably to be accounted for by differences in temperature. It should be 
remarked that Zuk employs as the temperature of the critical point 2337°. The 
formula used by Zuk is one given by Avenarius, viz.:— 
V=220*59-50*91 log (2337-0- 
As this formula is entirely empirical, there is nothing to be gained by its use, 
although it appears to give an approximation to the found results. 
17. We are now able to give the specific volumes and specific gravities of liquid 
alcohol at definite intervals of temperature and at pressures equal to the vapour- 
pressures at those temperatures. They are given in the following table. They are 
read from a smoothed curve representing individual observations of temperature and 
volume, and checked by means of the curves representing compressibility for known 
rise of pressure at constant temperature. In Plate 3, the observations shown by 
circles determine the direction of each curve. The curve connecting their terminals, 
which exhibits relations between the volume of the liquid, the temperatures, and the 
pressures equal to the vapour-pressures at those temperatures, was constructed by 
correcting the volumes when not read at the true vapour-pressures to the true 
volumes at those pressures. The curve was drawn through the points thus obtained, 
and it was seen that the points of intersection of these curves confirmed the position 
of points on a curve representing the relations between volumes and temperatures at 
the vapour-pressures corresponding to the temperatures. We would suggest the 
