WORK OF M. R. SCHMIDT. 



We have seen that certain definite relations exist between the conductivity of 

 various electrolytes dissolved in binary mixtures of several solvents and the vis- 

 cosities of their solutions. It was of interest to know whether similar relations 

 would hold when one of the component solvents had a viscosity much greater than 

 that of the other; in other words, whether the effect of one solvent on another follows 

 the same laws, no matter what substances are used. The solvent eminently suited 

 for this purpose is glycerol. Not only is its viscosity enormously greater than that of 

 any other homogeneous liquid at ordinary temperatures, but several of its physical 

 constants would lead us to expect glycerol to be well adapted as a solvent to making 

 conductivity measurements. The dielectric constants and association factors of 

 the solvents used in the previous work are given in table 103. The dielectric con- 

 stants are taken from the work of Drude, 1 and were all determined in the neighbor- 

 hood of 18; and the association factors are taken from the work of Ramsay and 

 Shields, 2 and refer to nearly the same temperature. 



Table 103. 



Glycerol has a dielectric constant of 16.5 at 18, and hence, in terms of the 

 Thomson-Nernst rule, should have a fairly high dissociating power. Moreover, 

 if we assume Dutoit and Aston's hypothesis to hold even approximately for glycerol, 

 the association factor of the latter, 1.80 at 20, would lead to the same conclusion. 

 The conductivity data will show that these expectations are well founded, and that 

 glycerol is, in all probability, a solvent with a dissociating power rather above the 

 average. 



GLYCEROL AS A SOLVENT. 



It has, of course, been known for a long time that glycerol has remarkable solvent 

 properties. Not only will it dissolve deliquescent salts, such as many compounds of 

 lithium and calcium, but it also takes up large quantities of nearly all the halogen 

 salts of the common metals, including even those that are difficultly soluble in water, 

 as well as many sulphates, nitrates, etc. In addition, the alcohol groups of glycerol 

 react with metallic oxides and hydroxides, forming glycerates by a process analogous 

 to the solution of sodium or potassium hydroxides in alcohol. 



'Weid. Ann., GO, 500. 



=Zeit. phys. Chem., 12, 433 (1893). 



133 



