CINEOL AS A SOLVENT IN CRYOSCOPY. 467 



OINEOL AS A SOLVENT IN CRYOSCOPY. 

 By Charles E. Fawsitt and Christian H. Fischer. 



[Read before the Royal Society of N. 8. Wales, December 5, 1917.^ 



Oeneol is an important constituent of many Eucalyptus oils 

 and it is now easily procurable in a fairly pure condition. 

 Its composition is given by the formula Ci H I8 O. It was 

 thought that its value as a possible solvent for cryoscopic 

 determinations was worth investigation. 



The cineol was* obtained from Hudson's Eumenthol Co., 

 Sydney, where, we understand, it is obtained from eucalyptus 

 oil, which is rich in cineol. The cineol is obtained from the 

 oil by freezing out this constituent. We distilled the cineol 

 and found that most of it came over at 175° - 176° C. 

 The freezing point of the distilled cineol was 0*1° C. The 

 figure usually given for the freezing point of cineol is — 1°0., 

 but this latter figure is too low. 



Pure cineol is exceedingly hygroscopic, and owing to the 

 relatively small molecular weight of water, small amounts 

 of absorbed water depress the freezing point very much. 

 An addition of 0*2% of water was found to depress the 

 freezing point of cineol 0*54° C. 



In order to test whether the distilled cineol had any 

 considerable amount of moisture in it, a current of air, dried 

 by sulphuric acid, was passed through the solution for three 

 quarters of an hour, when the freezing point rose to 0*2° O. 

 Some distilled cineol was next allowed to stand over sodium 

 for twenty-four hours and redistilled; its freezing point 

 was found to be 0*9° C. 



Cineol as a Solvent in Cryoscopy. 



For the first determinations given below, distilled cineol 

 of F.P. 0*1° C. was used. This contained a small quantity 



