374 



AMPHOTERIC COLLOIDS. Ill 



If instead of giving one washing we give four washings with 25 cc. of 

 HoO after the acid has drained off, we avoid the low values of pH 

 completely and the drop in the curves for swellingdisappears (Fig. 



H Br M A _«. _1 Jl-=^ M -^ " JL li H M H 



cone a 16 32 64 m^h^wm su m xm mi icsw 



i3 i4 17 40 il'^-^'i^'Vi il i7 i? 17 S8 &3 



Fig. 6. See explanation under Fig. 5. 



7). The parallelism between the curves for bromine number, for os- 

 motic pressure and swelling is now practically complete. 



The curves show distinctly that the independent variable is the 

 bromine number. Thus in Fig. 7 this number was slightly in ex- 



