228 RELATION OF PHYSICAL PROPERTIES OF AQUEOUS SOLUTIONS 



change, we shall have as the value of the property for the 

 mixture, assuming no change of volume on mixing, 



the n's being numbers of gramme-equivalents per unit volume 

 of the original simple solutions, and i' and a 2 f being the 

 ionization-coefficients in the mixture As the values of the k's 

 and I's have been determined above for sodium and potassium 

 chloride for a number of properties, and, as I have shown in rny 

 paper on the " Conductivity of Mixtures," cited above, how the 

 ionization-coefficients after mixing may be determined, it should 

 be possible to predict the values of these properties for mixtures 

 of solutions of these salts. 



The following tables show that this can be done. The 

 ionization-coefficients were determined in the way described in 

 the paper referred to. The constants k and I employed in the 

 calculations were those determined above. The observations 

 were made by the authors whose determinations for simple 

 solutions were used above ; in fact in most cases it was the 

 solutions of the tables given above which were mixed. The 

 limits of experimental error are thus of about the magnitudes 

 mentioned above in each case. All remarks made above with 

 regard to the reduction of observations to 18 C., the values of 

 the property for water, etc., apply also to the mixtures. In all 

 cases, except that of surface-tension, the solutions mixed were 

 mixed in equal volumes. Unfortunately, Bender made no 

 observations on the refracting power of mixtures. 



