JACQUES LOEB 



589 



at a pH of about 4.0. The isoelectric point of egg albumin is, accord- 

 ing to Sorensen,^ at 1.5 X 10"^ n or pH about 4.8. 



IV. Membranes Treated with Oxyhemoglobin. 



Defibrinated ox blood was diluted repeatedly with isotonic solu- 

 tions of NaCl and centrifuged to remove practically all the proteins 



Collodion membrane treated with oxyhemoglobin 



pn 1 2 3 4 5 6 7 8 9 10 11 12 



isoelectric 



point 6.75 

 Fig. 5. Collodion membranes treated with oxyhemoglobin. Reversal of sign of 

 charge of membrane at pH of about 6.0, on the acid side of the isoelectric point of 

 oxyhemoglobin. 



^ Sorensen, S. P. L., Compt. rend. trav. Lab. Carlsberg, 1915-17, xii. 



