THE ACTION OF NEUTRAL SALTS 



91 



will designate this value as relative viscosity. The addition 

 of the NaCl causes only a drop, and no rise in the curve. 



LO 



nMlLN-KKKKN N N N 

 U 8192409620481024512 256 128 64 32 16 8 



Concentration 



FIG. 26. Difference in the effect of different concentrations of NaCl and of 

 HC1 on the relative viscosity of an 0.8 per cent solution of gelatin chloride of 

 pH 4.0. In the case of NaCl we observe only the depressing effect of the Cl ion; 

 in the case of HC1 we notice an augmenting effect of the H ion and a depressing 

 effect of the Cl ion, the latter prevailing as soon as the concentration of acid 

 added is > N/256. 



If, however, the 1.6 per cent gelatin solution of pH 4.0 is mixed 

 with various concentrations of HC1 (upper curve, Fig. 26) instead 



