DISCUSSION OF RESULTS. 



IT would be desirable for some reasons to discuss the facts brought out by 

 our study of conductivity in one section, and the results of the work on fluidity 

 in a separate section ; but on account of the close relations between conduc- 

 tivity and fluidity it seems best to take up the discussion in such a manner as 

 to bring out more clearly the bearing of these relations upon one another. 



An explanation of the minimum in molecular conductivity has been offered 

 by Jones and Lindsay, 1 and, as has already been pointed out in the introduc- 

 tory section of this paper, this has been experimentally substantiated by the 

 work of Jones and Murray. 1 This explanation was, however, applied only to 

 the cases where an actual minimum occurs, but, as we have already pointed 

 out, there are fully as many cases in which the curves show simply a falling 

 below the values as calculated from the rule of averages. We have shown that 

 in these cases we have what we may call a virtual minimum, and we extend 

 the hypothesis of Jones and Lindsay to these cases also, since it bears as we 

 believe on both the actual minima and the virtual minima. Since these two 

 conditions cover by far the greater majority of the conductivity results that 

 have been obtained up to the present in mixed solvents, it appears that the 

 hypothesis of Jones and Lindsay when applied to the problem of conductivity 

 in mixed solvents is perfectly general. 



A further proof of this explanation has been brought out by our study of 

 fluidity. A marked minimum in fluidity occurs in the 50 per cent mixtures 

 of water and methyl alcohol, water and ethyl alcohol, and water and acetone. 

 It is in these same mixtures that the minimum in conductivity occurs. 



F. H. Getman, 2 in discussing the maximum viscosity (or minimum fluidity, 

 which occurs when the alcohols and water are mixed, drew the conclusion 

 that if the association of one liquid is diminished by the presence of another 

 associated liquid, then the viscosity of a 50 per cent mixture of these liquids 

 should be less than the viscosity as calculated from the rule of averages. This 

 conclusion, as we shall see, is erroneous. The work of Thorpe and Rodger 3 

 has clearly shown that viscosity may be taken as the sum of the forces in play 

 between the molecules. Therefore, when two associated liquids are mixed, 

 if they mutually decrease the association of one another, the total number 

 of molecules in a given volume of the mixtures is increased, and consequently 



1 Loc. cit. 2 Journ. chim. Phys., 4, 403 (1906). 3 Phil. Trans., 185A, 307 (1894). 



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