DISCUSSION OF RESULTS. 107 



DISCUSSION OF RESULTS. 



The curves for the conductivity of potassium iodide in all of the different 

 mixtures are very similar to the curves of fluidity in the corresponding mix- 

 tures. Lithium nitrate and calcium nitrate in all mixtures, at low tem- 

 peratures, show a deviation from the fluidity curves, particularly in the 75 

 per cent mixtures, tending to produce a maximum in conductivity. 



The work of Jones and Lindsay and of Jones and Carroll showed that solu- 

 tions of lithium nitrate, in mixtures of methyl alcohol and water, gave curves 

 with a simple minimum, like the fluidity curves for the corresponding mixtures. 

 Calcium nitrate, dissolved in the same mixtures, and also in mixtures of ethyl 

 alcohol and water, in no case gave a minimum according to Jones and Carroll ; 

 consequently their curves are not similar to the corresponding fluidity 

 curves. 



Our results differ fundamentally from those heretofore observed, in that 

 the mixtures of acetone with the alcohols and water show a tendency towards 

 a maximum in the conductivity of solutions of certain salts, such as lithium 

 nitrate and calcium nitrate. 



Since conductivity is dependent upon fluidity, and not vice versa, we shall 

 discuss first the fluidity curves, and then the conductivity curves in connec- 

 tion with them. 



When methyl alcohol or ethyl alcohol is mixed with acetone, the fluidity 

 curve of the mixtures is a straight line. This is what we should expect, if the 

 fluidity of each of the components has its proportionate effect. Hence we 

 may conclude that the molecular aggregations of these pure solvents are not 

 essentially changed in regard to size by mixing the two solvents. We have 

 already shown that the work of Thorpe and Rodger, Traube, Varenne and 

 Godefroy, and others has made it evident that viscosity is dependent upon 

 the character of the molecular aggregations present. 



It may be objected that a straight line is not the "normal" fluidity curve, 

 since, heretofore, a straight line has been considered to be the normal viscosity 

 curve, and the two conceptions are, in general, incompatible. To make this 

 clear, let us suppose that we mix two liquids which are made up of particles 

 which have no unusual action on each other, i. e., do not form new aggrega- 

 tions of any kind. Two monomolecular liquids which do not form complexes 

 on mixing would fulfill this condition. Further, let us suppose that the liquid 

 is allowed to flow through a tube. The resulting fluidity would be the sum 

 of the partial fluidities of the components. That is, the more rapidly moving 

 particles would be held back by the slower ones, and the motion would be 

 a mean value, proportional to the relative amounts of the components. For- 

 mulated, this would be 



(1) 



