418 



As set forth loco citato, the attending- cation lessens the negative 

 charge of the nebnia of this acid. Conseqnenilj salicylic acid and 

 salicylates, in weak concenlralions, determine the electrifying power 

 of the nel)nla in quite the same wa^' and with a negative sign, 

 only with qnantilalive ditferences in snch a sense that the salt 

 prodnces a lower chai'ge than the acid, and can be sprayed in 

 highei' concentrations on acconnl of greater solnbility in water. This 

 also holds good for oiher salicylates that are soluble in water. 



The negative charge of salicylas natricus lessens with the increase 

 of the concentration, so that it gradually approaches the zero-line, 

 and ultimately crosses it. The charge, then, is positive. For a long 

 time there is no charge at all, as is well seen in Fig. J, which 



Fig. 2 Negative and Positive phase of the Charge of salicylic acid and 

 the influence of Ü.0025 n. NaCI and of 6 '7o sugar on tlie charge. 



1-6 



♦ SI 



O 



-«, 



-V 



'It 

 -/y 

 -to 



'10 



efOectv 



; o,o\ "»v/ 



-V 



-3 



1. Curve of the Charge of Salicylic acid alone. 



2. id. of salicylic acid + salt. 



3. Id. of „ fl + sugar. 



Division of abscissa and ordinate as in Fig. 1. 



'X^. 



