492 



AMPHOTERIC COLLOIDS. IV 



The constant character of this ratio of the two pressures of 1 : 3 (or 

 3:8 for the uncorrected value) for the two valencies, but regardless 

 of the other qualities of the ions, betrays a stoichiometrical basis for 

 the influence of valency. The experiments were repeated to guard 

 against error, the results remaining the same. 



125 



100 



75 



50 



25 







4 



3 



Z 



pH 5.0 5.3 5.6 5.9 6.2 6.5 6.8 7.1 74 17 8.0 83 

 Ca(0H)2 



Fig. 6. See explanation under Fig. 2. 



125 

 100 



25 



pH 4.8 5.1 5.4 57 6.0 £3 66 69 72 75 78 

 Ba(0H)2 



Fig. 7. See explanation under Fig. 2. 



This means that in a 1 per cent solution of a metal gelatinate we 

 have approximately three times as many particles in solution or sus- 

 pension when the metal is univalent as when it is bivalent. Before 

 we can draw any further conclusions we have to consider the relative 

 conductivities of the same gelatin solutions. 



