HBr 

 cone 



n n n_ _m JlJlJl_tLiLJlJL-d Il- 

 ls 3Z 64 IZ6 256 512 I0Z4 ZM6 «>% 8102 16364 3Z7£a 65536 



1.4 1.8 24 2.8 3.3 4.0 4.6 11 55 6.Z 6.6 6.5 ( 



Fig. 2. Curves for bromine number (cc. 0.01 n Br in 25 cc. of 1 per cent gelatin 

 solution), conductivity, and osmotic pressure of gelatin in presence of various con- 

 centrations of HBr. Abscissae as in Fig. 1. No parallelism between curve for 

 osmotic pressure and curves for bromine number and conductivity. Curve for 

 osmotic pressure has minimum at pH about 4.6, maximum at pH = 3.3, and then 

 drops. No conclusion can be drawn from such experiments as to the "colloidal" 

 or true character of osmotic pressure. Osmotic pressure measured in height of 

 column of 1 per cent gelatin solution. 



369 



