1274 



As may be expected the consequence is that salicylic acid and 

 salicvlic acid salts determine the electrifying |)Ower of the nebula 

 in a similar way, there being only a quantitative difference in such 

 a sense that the salt produces a lower charge than the acid. 



An intercomparison of the various concentrations of the acid, 

 which is best expressed in a graphical way, shows that the optimum 

 electrifying power of salicylic acid is located at about J millinormal; 

 beyond it or below it the charge of the nebula is much weaker. 

 Such an optimum is not only lowered, but also shifted by the 

 coincidence of a cation, so that for salicylas natricus e.g. under 

 the same conditions it is located in the 6 per-mille.-concentration. 



We have made an attempt to compare the univalent cations with 

 regard to their capacity of shifting the optimum and of depressing 

 the chai'ge. When taking a 1 millinormal solution of the salicylic 

 acid, the deflections of the electroscope will decrease proportionally 

 through the addition of cations. The following table gives the 

 factors by which the deflection of the electroscope, caused by the 

 salicylic acid alone, must be divided in order to find the deflection 

 that appears when adding a certain salt to the salicylic acid: 



Factor by which the deflection of the electroscope is reduced, when spraying 



a mixture of 0,001 n. salicylic acid and the chloride of the subjoined 



alkalimetals, instead of spraying 0,001 n. salicylic acid alone. 



It will be seen that the charge of the nebula decreases gradually 

 from left to right. The factor reducing the deflection increases from 

 Lithium to Ammonium. 



Li. < Na. < K. < Rb. < Cs. < i\H,. 



which calls to mind the known lyotiope series. Our nebula is also 



