and on the Preparation of Glycol. 435 



papers. It leaves an oil-spot on papeVj which disappears after 

 some time. It is a little heavier than water, and dissolves in it 

 in all proportions. It is readily decomposed by potash and by 

 baryta into acetic acid and glycol. Its boiling-point is from 

 181°-182° C. The following analytical determinations were 

 made: — 0"308 grm. gave Ooll grm. carbonic acid and 0'2185 

 grm. water, which agrees best with the relation C H^ 0^, as is 

 here seen : — 



Calculated. FouuJ. 



C = 48 = 46-0 45-1 



H^ = 8 = 7-7 7-8 



03 =J^ = 46-3 



104 100-0 



The formula C"*H^03 is that of a monoacetate of glycol, 

 C^ IP 1 

 C^ IP >■ 0^. In order to control this, the following acetic acid 



. ^^ -J. 



determinations were made : — 2*027 grms. of substance were en- 

 closed in a tube with some moist hydrate of baryta, and the 

 sealed tube heated in a paraffine bath for twenty-five hours to a 

 temperature of 120°-130° C. The contents of the tube were 

 then transferred to a flask, and carbonic acid passed throvigh to 

 saturation ; the mixture was then heated for some time and 

 filtered; and in the filtrate, which contained acetate of baryta, 

 the baryta was determined as sulphate. In this way 2"136 

 grms. of sulphate of baryta were obtained, which correspond to 

 2-33 grms. acetate of baryta, or to I'l grm. acetic acid. Accord- 

 ed H" ~] 

 ing to the formula of monoacetate of glycol, C^H^O >0^, it 



H J 

 VfOuld yield, by decomposition with hydrate of baryta, one equi- 

 valent of acetate of baryta, thus : — 



C2 H3 1 0^ -h Ba HO = C^ W BaO^ + ^" JJ^T O^. 



II J Hydrate of Acetate of ^^ J 



Monoacetate of baryta. baryta. t^lycol. 



glycol. 



And 2-027 grms. of substance ought to give 2-485 grms. of 

 acetate of baryta ; the quantity obtained, 2-33 grms., corresponds 

 therefore to O-'J !• of an equivalent of acetic acid. The diacetate, 



2 (C^ II C)\ I ^*' would have given 3*49 grms. acetate of baryta. 



In a second determination made by the same method, but with 



substance of a different preparation, 1-825 grm. gave 2-027 grms. 



2F2 



