FIG 2 



The Coagulation of Arsenious Sulphide Sol by Cobaltic Complexes 5 



present experiment. So far as the present investigation was con- 

 cerned, it gave a curve, as shown by Fig. 1, in place of a straight 



hue. Freundlich [Zs. physik. 

 Cheni.,73, 385, (1010)] calcu- 

 lated approximately the pre- 

 cipitating concentration8 \)y 

 utilizing the adsorption curve 

 and by assuming that the 

 neutral salts in their equiva- 

 lent solutions are, in despite 

 of their valencies, adsorbed in 

 the same manner. His idea 

 can be expressed also as 

 follows: Since the electric 

 charges of mono-, di- and tri- 

 valent ions are in the ratio of 

 1:2:3, the amounts which 

 should be adsorbed causing a 

 complete coagulation should 

 be in the ratio of 3 : 1"5 : 1, 



and if we plot the logarithm 

 Lop- (Valency) ' , • •. ^• 



*' 01 the precipitating concentra- 



tions against those of the numbers , i.e. 3, I'o and 1 for 

 mono-, di- and trivalent ions respectively it would give a straight 

 line. 



It seems that this idea of Freundjich was clearly verified by 

 the present investigation. Taking the logarithm of the valencies 

 of the cobaltammines as abscissa and those of the limiting values 

 (for convenience the author took the values given in the third row 

 of the table III) measured by the method already described, as 

 ordinate, a straight line, as shown by Fig. 2, was obtained. From 

 th'e diagram the author was able to deduce the following equa- 

 tions : 



Log Sn -hi^ Log N -f- a = 



(1) 



