226 RELATION OF PHYSICAL PROPERTIES OF AQUEOUS SOLUTIONS 



to only the first five of the above observations. To represent 

 the viscosity of stronger solutions he had to introduce a term 

 expressing the effect due to the mutual action of the molecules 

 of salt. KC1. All six observations were used. The agreement 

 in this case is quite satisfactory. 



Surface-Tension. NaCl. Only two observations on suffi- 

 ciently dilute solutions were available, and the applicability of 

 the formula cannot therefore be tested. The constants were 

 found, for use in the calculation of the surface-tension of 

 mixtures. KC1. The first four observations were used, and the 

 agreement is quite satisfactory up to a concentration of 3 grm.- 

 raols. per litre. 



Refractive Index. In the case of both salts the first three 

 observations were used, and in both the agreement is quite satis- 

 factory up to a concentration of about 2 grm.-mols. per litre. 



The above tables seem to be at any rate quite consistent 

 with the possibility of expressing the values of at least five of 

 the physical properties of moderately dilute solutions in terms 

 of their state of ionization. I hope to find leisure at an early 

 date to extend the investigation to solutions of salts and acids 

 of a more complex character and to other properties. 



The following are the ionization-constants used in the above 

 calculations : 



