PROTEINS 159 



As in the case of albumin, the globulin ions are responsible for the 

 internal friction. Though the internal friction of globulin in neutral 

 salts is low, it is considerably higher in the ionized solutions occurring 

 in acids or alkalis; the viscosity is highest hi the case of alkali 

 salts of globulins which are ionized most strongly and least hydrolyzed. 

 The viscosity rises disproportionately with concentration and, in fact, 

 the increase for alkali globulin > for acid globulin > for neutral salt- 

 globulin (W. B. HARDY* 2 ). 



W. B. HARDY gives the following viscosity values for 7.59 gm. 

 globulin per liter: 



Water 1 



MgSO 4 -globulin 4.66 



HCl-globulin 15.5 



NaOH-globulin 67.9 



He derived these velocities for globulin ions: 



Acetic acid-globulin 23 1Q- 6 cm. per second 



HCl-globulin 10-1(H " " " 



NaOH-globulin 7.7 1<H " 



W. B. HARDY regards solutions of globulin in neutral salts as 

 molecular combinations, since, in contrast to solutions in alkalis or 

 acids, they are thrown down upon dilution. It can be understood 

 from the dominant acid character of globulins that a neutral salt 

 solution of globulins is precipitated by acids. Though alkali globulin 

 solutions are permanent in the presence of neutral salts, acid globu- 

 lins are precipitated by them. 



According to W. B. HARDY, serum contains no globulin ions. 



If serum is kept warm for a long time (e.g., 2 hours) below its 

 coagulation temperature, the amount of globulin is increased at the 

 expense of the albuminous portion (MoLL*). This formation of 

 globulin is either impeded or entirely stopped by salts. 



"Artificial globulins" is the designation of the substances pre- 

 pared from egg albumin by ANDRE MAYER.* He found that when 

 he added to egg albumen a certain quantity of a solution of a salt of 

 a heavy metal ZnS0 4 , Zn(NO 3 ) 2 or a positive colloid (colloidal Fe 2 3 ), 

 the resulting precipitate was insoluble in water and in solutions of 

 nonelectrolytes, but, on the contrary, it was soluble in solutions of 

 salts (e.g., NaCl, Ca(N0 3 ) 2 , etc.). With these facts in mind, we must 

 consider the suggestion made by A. MAYER that globulins are com- 

 plexes of albumins (possibly with other positive colloids). 



