PROTEINS 153 



reversible flocculation of albumin in the cold, but with greater con- 

 centration (from about 0.03 normal up) an irreversible flocculation. 

 Here also the anions have an unequal influence, which is arranged in 

 an order the reverse of that obtaining for neutral albumin, namely, 



S0 4 < Cl< NO 3 < Br < SON. 



This series, accordingly, does not agree with the other one in all 

 respects. 



It is quite evident in the case of the acid salts that their action is 

 the combined result of the acid albumin formed and the action of 

 the salt itself. The process is, therefore, quite complicated. 



Alkali Albumin. 



There is a far-reaching parallelism between alkali albumin and 

 acid albumin. Alkali albumin like acid albumin is not coagulable 

 by heat or alcohol (even 0.003 normal NaOH inhibits the heat coagu- 

 lation of amphoteric albumin) ; its viscosity is greatly increased, its 

 surface tension diminished; excess of alkali restores the precipitability 

 by alcohol and again decreases the internal friction; it migrates to the 

 anode. ST. BUGARSZKY and L. LIEBERMANN* showed that NaOH was 

 bound by albumin, and that albumin depressed the freezing point of 

 soda-lye. Neutral salts arrest the action of alkalis; in contradis- 

 tinction to acid albumin it is the cations to which the greatest signifi- 

 cance attaches, and, in fact, the effect of the divalent earth alkalis 

 (Ca, Sr and Ba) and the divalent magnesium very greatly exceeds 

 that of the monovalent alkalis. Though heat coagulation does not 

 occur at all or advances only to a milky turbidity (e.g., the effect of 

 1.2 normal KC1 was doubtful), in alkali albumin containing large 

 quantities of alkaline salts the ability of alkali albumin to coagulate 

 with 0.003 normal NaOH is demonstrable upon the addition of 

 0.0002 normal CaCl 2 . 



Additions of neutral salts bring about a decrease of internal friction 

 in a manner analogous to their influence on heat coagulation, and, in 

 fact, a small addition of salt has a proportionately greater effect 

 than a large one. Moreover, the earth alkalis greatly exceed the 

 alkali salts in their ability to diminish internal friction. 



The salting out of alkali albumin requires a greater concentration 

 of alkali salts than is required for neutral albumin; the product is 

 reversible and the anions are effective in the same order as for neutral 

 albumin. 



In general, the relations are simpler for alkali albumin than for 

 acid albumin. In the former, they depend upon the electrolytic dis- 



