﻿Expansion of Liquids and their Critical Temperatures. 659 

 Table II. 



Liquid. 



Coef. of 9 (Calc). Coef. of 9 (Exp.). 



. 179x 

 .! -79x 

 .! l-36x 



Acetone 



Aniline 



Bromine „ 



Benzene I l*375x 



Pentane i 2*25 X 



Phenol '78x 



Toluol J 1T9X 



Naphthalene I '67X 



Thymol j *79x 



Xylol-o | 1*02 X 



Xylol-m .. ! 107X 



10 



IO" 6 



10-6 



IO -6 



lO' 6 



lO" 6 



io" 6 



lO" 6 

 10" 6 



io" 6 

 io" 6 



5-83x10 

 1-08 xlO -6 

 1-71 Xl0~ 6 

 2-18X10 -6 

 4-08X10 -6 

 •708xlO _(5 

 2-49X10-* 

 •28xl0" 6 

 •43X10- 6 

 1-77x10-6 

 1-02X10' 



• 6 



Not much weight can be attached to the values of the 

 coefficients o£ 6 as Mathias' law is not sufficiently accurate to 

 allow of second-order quantities being deduced therefrom. 

 The experimental values likewise are of doubtful value. It 

 is interesting to note, however, that the order of magnitude 

 agrees in every case. 



The relation does not hold for liquids which show strong- 

 association. This was expected, as the law of the rectilinear 

 diameter fails for such liquids. 



Thorpe and Riicker * have obtained an equivalent result, 

 and have shown how critical temperatures can be calculated 

 from the formula T T 



where Si and * 2 are two densities of a liquid and A is a con- 

 stant which they take to be 1*995. This can be changed into 



the form 



s 

 *m _m = constant, 



which is equivalent to equation (4) above. They obtained 

 their result by using an expression for the expansion of a 

 perfect liquid f, proposed by Mendelejeff as a result of his 



experimental work on the Paraffins, coupled with Van 

 Waals' equation of state. 



I wish in conclusion to thank Prof. A. W. Porter for 

 kindly help and criticism, and for supplying me with 

 reference to the work of Thorpe and Riicker. 



* Thorpe & Riicker, Trans, Chem, Society, xlv. (1881). 

 f Mendelejeff, Trans. Chem. Soc. xlv, (1884), 

 2X2 



der 



his 

 the 



