JACQUES LOEB 735 



should, however, be stated that this sharp line of demarcation was 

 not found to exist in all solutions. As a consequence the figures 

 of this table serve mainly the purpose of confirming the two rules. 

 The first vertical column gives the molecular concentration of the 

 solution of the electrolyte which was in every case selected so that on 

 the assumption of complete electrolytic dissociation the solution was 

 isosmotic to a m/64 solution of cane sugar. These solutions were, 

 of course, not strictly isosmotic but we shall see in Chapter VIII that 

 such small differences in osmotic pressure as occurred in these ex- 

 periments cannot influence the result, on account of the fact that the 

 maximal value of the electric force is generally reached in concentra- 

 tions of the electrolytes lower than those used in this table and that 

 a further rise in concentration of the electrolyte does not materially 



affect the value of e. For this reason we must not deduct ~r from the 



64 



concentration of the balancing solution in order to get the value of 



e, but a much smaller figure which will fall within the limits of the 



exactness of our methods. Therefore, the concentration of the 



balancing solution of cane sugar can be considered as a rough 



approximation of the value of e. 



The second vertical column gives the nature of the electrolyte, the 

 third the pH of the solution, and the fourth the approximate molecular 

 concentration of the balancing sugar solution. The fifth column gives 

 the value e in terms of atmospheres of the balancing solution. All the 

 values of the balancing concentration are only rough approximations. 



These data find their full explanation on the basis of the two rules 

 expressed at the end of Chapter I. 



First we notice that the electrolytes of the first group {A , in Table 

 V) possessing univalent or bivalent cations attract water as if the 

 molecules of the water were positively charged bodies. Thus the 

 concentration of the balancing solution (and the value of e) increases 

 with the increase in the number of charges of the anion and diminishes 

 with an increase in the number of charges of the cation — the latter 

 acting as if it repelled the positively charged water molecules. 



We also notice that in Group A the repelling action of the cation 

 increases inversely with its "atomic radius," the lithium salts having 

 a lower balancing concentration and a lower value of e than the 

 sodium or potassium salts with the same anion. 



