THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



DECEMBER 1893, 



L. The Dissociation of Compounds in Water as Measured 

 by the Lowering of the Freezing-Point, and some It 

 tions with Organic Compounds. By Harry 0. Jones *, 



[Plates IV. to IX.] 



THAT the molecules of compounds like the common salts 

 dissociate into parts when dissolved in water has been 

 shown by such independent lines of evidence that it can no 

 longer be reasonably doubted. It has also been found that 

 alkalies, acids, and many other compounds conduct themselves 

 in a similar manner. The qualitative fact being established, 

 it is of interest and importance to determine the amount of 

 dissociation which compounds undergo when different quanti- 

 ties are dissolved in water. The problem, then, is to measure 

 the dissociation of compounds in solutions of different con- 

 centrations. 



There are several possible methods which can be applied 

 for this purpose with more or less accuracy. These are — the 

 osmotic pressure of the solution, the raising of the boiling- 

 point of the solvent, the lowering of the freezing-point of the 

 solvent, the effect of one compound on the solubility of 

 another, and the conductivity of the solutions. Other methods, 

 as "inversion " of sugar, and " saponification " of ethers, are 



* Communicated by the Author. 

 Phil Mag. S. 5. Vol. 36. No. 223. Dec. 1893. 21 



