498 



AMPHOTERIC COLLOIDS. IV 



the axis of abscissae are the logarithms of the concentrations of the 

 alkah solution used. The pH of the gelatin is given under each con- 

 centration. The values for Na and K gelatinate are practically iden- 



60 

 50 

 40 

 30 

 20 

 10 

 110 

 100 

 90 

 80 

 70 



. 60 



NaOH _t;1__M__M__M_M_J^M_M_ M_ M_ JM 



cone 8192 4096 2048 1024 512 255 128 64 32 16 8 



pH 47 47 48 SO 5.5 8.6 10.0 lO.I 10.2 10.3 10.4 



Figs. 9 to 12. Curves for viscosity and swelling of sodium gelatinate (Fi.s;. 9), 

 potassium gelatinate (Fig. 10), calcium gelatinate (Fig. 11), and barium gelatinate 

 (Fig. 12). The curves for sodium gelatinate dififer from the curves for Ca and Ba 

 gelatinate in the same sense and almost the same degree as the curves for osmotic 

 pressure. 



KOHconc. _M_ii_Jl_ M_M_ii.JlJlIlM_ M 

 8I9E 4096 2043 i024 5i2 256 l£8 64 32 16 6 

 pH 4.8 48 4.9 5.1 54 9.0 9.9 lOO lO.I 10.2 103 



Fig. 10. See explanation under Fig. 9. 



