390 Mr. H. 0. Jones on the Cryoscopic Relations 



Duplicate Series with Cane-Sugar. 



Grams 

 in litre. 



Normal. 



Lowering 

 found. 



Gram-mol. 

 Lowering. 



3*8875 



0-01136 



0-0247 



2174 



7-775 



0-0227 



0-0481 



2-119 



15-550 



0-0455 



0-0919 



2-02 



23-325 



0-0682 



0-1327 



1-946 



31-100 



0-0909 



0-1737 



1911 



The two series agree satisfactorily throughout. 



In these determinations a large volume of solution (1100 

 cub. centim.) has been employed, diminishing thus very 

 greatly the effect of disturbing influences from without. A 

 freezing-mixture was employed which was only a few tenths 

 of a degree colder than the freezing-point of the solution. 

 The stirring was carried out so gently that errors from this 

 source could not have assumed any appreciable dimensions, 

 and yet the molecular lowerings found are far above the 

 theoretical value, I can hardly conceive that anyone can now 

 claim with any degree of probability, that the cause of the 

 difference between the observed and calculated values is to 

 be found in the very cold freezing-mixture employed, or in 

 the heating of the solution by stirring, or that equilibrium 

 was not established in the solution, in consideration of the 

 amount of ice which was present, and the time which was 

 allowed for the equilibrium to establish itself. 



That somewhat lower values had been found for cane-sugar, 

 when a less vigorous freezing-mixture was used, led me to 

 investigate some other non-electrolyte, — ethyl alcohol was 

 chosen. Absolute alcohol was prepared by treating 95 per 

 cent, alcohol with lime, distilling, and allowing the product 

 to stand over anhydrous copper sulphate (CuS0 4 . H 2 0) for 

 several months. From a normal solution of the alcohol, the 

 more dilute solutions were prepared when needed. The de- 

 terminations were carried out exactly as with cane-sugar. 

 The temperature of the freezing-mixture was only a few 

 tenths of a degree lower than the freezing-point of the alco- 

 holic solutions. 



Results with Ethyl Alcohol. 



C 2 H G O = 46-03. 



Grams Normal Lowering Gram-mol. 



in litre. found. Lowering. 



1-0461 0-0227 0-0476 2-10 



2-0923 0-0455 0-0911 2-00 



3-1384 0-0682 0*1335 1'96 



4-1845 0-0909 0-1745 1-92 



( lhange in the freezing-mixture produced thus very nearly 



