KAHLENBERG— THEORY OF ELECTROLYTIC DISSOCIATION. 347 



cide which is the correct way to calculate the degree of dissocia- 

 tion, regarding which there are such excellent reasons to believe 

 that it has no counterpart in reality. Naturally then insur- 

 mountable obstacles must arise in determining the value. These 

 polemical discussions, however, are doing considerable good in 

 that they emphasize how inadequate the dissociation theory 

 really is, — they represent the beginning of the end of that the- 

 ory. 



v 



It is true that as soon as the theory of electrolytic dissociation 

 is declared invalid the original difficulty with the van't Hoff 

 theory of solutions 1 recurs, namely, the theoretical interpreta- 

 tion of the factor i. Whenever the factor i in the equation 

 PV=«RT, is unity we have the gas equation in its simplicity 

 as it holds for dilute solutions of the now classical cane sugar. 

 When in any case i is less than unity and diminishes as the con- 

 centration increases, the assumption that polymerization of the 

 dissolved molecules takes place can be made; but when i is 

 greater than unity, dissociation must be assumed. Arrhenius 

 assumed so-called electrolytic dissociation; from which it fol- 

 lowed that whenever a solution conducts electrolytically it re- 

 quires a corresponding factor i greater than unity, — that this 

 is by no means always the case has been sufficiently set forth 

 above. Again it has been shown above that, in the case of cane 

 sugar, for instance, a factor i which increases with the concen- 

 tration must be introduced. There is no other logical theoretical 

 significance to put upon this behavior than to assume that the 

 stronger the sugar solution is the more the solute dissociates. 

 This conclusion is absurd, — let alone the additional fact that 

 sugar solutions do not conduct. And cane sugar is by no means 

 the only non-electrolyte that behaves thus. Attention has been 

 directed to the fact that Dieterici found that the molecular lower- 

 ing of the vapor tension of dextrose and urea also increases with 

 the concentration like that of cane sugar. 



I am well aware that the gas equation is supposed to hold 

 strictly only for infinitely dilute solutions, just as it holds only 



^Compare in this connection, Crompton's explanation, Jour. Cheni. Soc. Lon- 

 don 97, 925 (1897). 

 4 



