140 Dr. Thomas Ewan on 



heat of dilution is alcohol, and even in this case the 

 determinations of the heat of dilution (Dupre and Page*) 



are not sufficiently numerous to allow of the values of , 



being calculated with any approach to accuracy. The 

 following table contains, however, the numbers which I 

 have obtained. The determinations of the freezing point 



are Raoult's.f 











Grams alcohol 



F 



k 



h 



1 



tolOOgr. H 2 0. 





highest. 



lowest. 



n 



i5* J 9 



267*2 



+ -0065 



+ •0139 



■0595 



19-56 



265-2 



-•O765 



-•OI47 



•0765 



2470 



262*4 



-•1254 



-'0454 



•0967 



29'!5 



260*2 



•I7II 



■0890 



-II4I 



40-68 



254'i 



•1851 



•1241 



'1591 



51-02 



248-7 



•1985 



■1545 



•1996 



59-66 



244-8 



•2405 



^365 



•2335 



70-iS 



240-9 



•3553 



•1788 



•2744 



values of t- obtained do not agree with each other. The 



I could find no interpolation formula which would 

 represent Dupre and Page's numbers for the heat of 



solution of alcohol, I, therefore, calculated -=-*-" from three 



aw 



different curves. Owing to the small number of deter- 

 minations (there were only five which I could use) the 

 curves could not be drawn accurately, and, therefore, the 



dQ 



chv 

 value of k has, therefore, been calculated by equation (4), 



using the highest and lowest values of j- found, and as will 



be seen the value of lies between these limits, except for 



the most dilute solution. 



It may be remarked that in this case (viz., alcohol 

 dissolved in water) k has the negative sign. 



* Phil. Trans., 1869, p. 591. 

 f Ann. Chim. Phys. (5) 20, p. 220. 1880. 



