344 



ON THE SUilFACE TENSION AND 



TABLE V. (Continued) SPECIFIC GKAVITY. 

 Copper and Potassium Sulphate Mixtures. 



It appears from the above Tables IV and V that the differ- 

 ences between calculated and observed values are within the 

 limits of error, throughout nearly the same range of concentra- 

 tion as that of the observations on simple solutions used in 

 determining the constants. This range is somewhat greater for 

 the Sodium and Potassium Sulphate mixtures than for the Cop- 

 per and Potassium Sulphate mixtures, which would seem to 

 support the view taken of these mixtures in my previous paper, 

 viz., as to the existence of a double salt in the solution. It 

 might also be mentioned here, in support of this view, that for 

 mixtures of stronger solutions of the Copper and Potassium 

 Sulphates than are here given, I have observed a quite noticeable 

 change of volume on mixing which is not the case for mixtures 

 of solutions of the Sodium and Potassium Sulphates for a like 

 concentration. 



As the ionization constants used in the calculations were not 

 determined from the observations of these tables, such alternation 



