162 



C. E. FAWSITT AND C. H. FISCHER. 



THE MIS0IBIL1TY OF LIQUIDS. 

 By Oharles E. Fawsitt, and Christian H. Fischer. 



[Read before the Royal Society of N. 8. Wales, November 5, 1919.'] 



When two liquids are shaken together they may (1) mix 

 perfectly in all proportions with one another, or (2) dissolve 

 partially in one another giving two layers, or (3) not mix 

 at all (appreciably). As examples of these cases we might 



take 



(1) ethyl alcohol and water 



(2) ether and water 



(3) mercury and water. 



It was noticed by Rothmund 1 that the chemical com- 

 position had some connection with the mutual miscibilities 

 and he drew up the following list of liquids in order: — 

 Water, lower fatty acids, lower alcohols, lower ketones, 

 lower aldehydes, nitriles, phenols aromatic aldehydes, ether, 

 halogen derivatives of hydrocarbons, carbon disulphide, 

 hydrocarbons. 



In such a case, liquids which are close together on the 

 list are miscible, while those furthest apart are the least 

 miscible. 



Later, Holmes 2 considered that the molecular volume 

 of the liquid was the determining factor in connection with 

 miscibility. According to Holmes, complete miscibility is 

 possible only when the molecular volumes are rather close 

 numerically. 



Holmes' conclusions are based on the supposition that 

 the molecules are spherical. While this premise is very 



1 Zeit. fur physikal. Chemie, 26, 489, (1898). 

 2 Trans. Chem. Soc , (1913) 103, 2147. 



