180 



THEORY OF COLLOIDAL BEHAVIOR 



tion be due to the anion; and this is the case, as Fig. 46 shows. 

 The gelatin chloride solutions were made up in different concen- 

 trations of the salts, NaCl, NaNO 3 , CaCl 2 , and Na 2 SO 4 . The 

 pH of the mixtures was always 3.5. Collodion bags of a volume 



M. 

 8 



M. _M M. M 



128 64 3Z 16 8 4 



Concentration of salts 



FIG. 46. Depressing effect of neutral salts on the osmotic pressure of a 1 per cent 

 solution of gelatin chloride of pH 3.5. 



of about 50 c.c. were filled with the gelatin chloride-salt mixtures. 

 These bags were dipped into beakers containing 350 c.c. of a 

 solution of the same inorganic salt of the same concentration 

 as that contained in the gelatin solutions, but these outside 

 solutions contained no gelatin. The pH of the outside solutions 



