80 G. J. BUEROWS. 



In discussing the variation of the specific solution volume 

 with concentration of solutes in aqueous or alcoholic solu- 

 tions, one other factor has been constantly overlooked. The 

 formulae (Equations I and II) from which the solution 

 volume of a solute is calculated, must give rise to regular 

 variations of v s or </> with A, in all cases where the volume 

 of the solvent, is altered by the process of solution. In the 

 above equations, if the solvent contracts during the process 

 of solution, this contraction is attributed wholly to the 

 solute. Thus in the equation : 



100 + A _ 100 



v s = _di ch_ (I) 



A 



the term—- is taken to represent the volume of 100 grams 



do 

 of water in all solutions, no matter what the concentration 



of the solute may be. These formulae are strictly applic- 

 able only in the investigation of solutions of the same solute 

 in different solvents. Thus if solutions of a certain solute 

 in two different solvents be prepared, and the solution 

 volume of the solute in each be calculated, the relative 

 values of v s or </>, may in these cases be taken to represent 

 the relative volume changes in the system solute-solvent. 

 Results obtained in this way afford us information as ta 

 the relative order of volume changes produced by dissolving 

 a certain solute in different solvents. But the formulae are 

 not applicable to the study of the effect of different con- 

 centrations of a solute in a particular solvent. It is quite 

 illogical to assume that the volume of one constituent of a 

 solution is unaltered over a wide range of concentrations 

 and then to attempt to explain the variations in the volume 

 of the other constituents, deduced by means of this assump- 

 tion. Let us consider for example, two solutions of a 

 certain solute in water, in both of which A is small, but in 

 one case much greater than in the other. Furthermore, 

 we will assume that the process of solution causes a con- 



