SPECIFIC GRAVITY OF AQUEOUS SOLUTIONS. ARCHIBALD. 347 



in the preparation of the solutions, and in the calculations, the 

 agreement between observed and calculated values seems to me 

 to be* exceedingly satisfactory, and to justify the conclusion that 

 even in this yery complex case it is possible by aid of the dis- 

 sociation theory to predict the specific gravity within the limits 

 of experimental error. 



Summary of Conclusions. 



(1.) Expression (1) represents observed values of the sur- 

 face tension and specific gravity of the solutions examined 

 through a range of concentration extending from 0.05 to about 

 0.4 or 0.5 equivalent gramme-molecules per litre. 



(2.) It is possible by aid of the dissociation theory of elec- 

 trolysis to predict the surface tension and specific gravity of 

 mixtures of Potassium and Sodium Sulphate solutions and the 

 specific gravity of mixtures of solutions of Potassium and 

 Copper sulphates throughout nearly the same range as above, 

 within the limits of the error of observation. 



(3.) It is possible by aid of the above theory to predict the 

 specific gravity of mixtures of solutions of Potassium Sulphate 

 and Sodium Chloride within the limits of experimental error. 



