Studies on So-Called Protective Ferments. 



3 



upon the colloidal complex of living matter. The compound used 

 in obtaining the results described would have a neutralizing or 

 coagulatory effect on protoplasm. Other reagents, facilitating 

 hydratation, have been used on ovaries from which seeds have 

 been obtained, the capacities of which are yet to be tested. 



2 (934) 



Studies on so-called protective ferments. II. Proteolytic enzyme 



is not specific. 



By J. Bronfenbrenner. 



[From the Pathological and Research Laboratories of the Western 

 Pennsylvania Hospital, Pittsburgh, Pa.] 



If the serum of a pregnant woman is placed in a dialyzing 

 thimble together with placenta in all respects as for an Abder- 

 halden test, only at a temperature of o° C, dialysis does not take 

 place. Both the serum and placenta however undergo certain 

 changes. Such a serum, when separated from the placenta and 

 placed in the dialyzing thimble with fresh placenta, can no more 

 induce any specific changes in placenta. And the placenta once 

 placed in contact with a positive serum on ice and then separated 

 from it, although it is not able to give up dialyzable substances 

 by itself (if suspended in salt solution), acquires the property to do 

 so in presence of any positive or negative, male or female fresh 

 serum. The placenta was evidently "sensitized" and the serum 

 exhausted of the specific substances present in pregnant serum. 

 Moreover such a serum deprived of its specific properties still 

 retains the ability of causing the appearance of dialyzable sub- 

 stances in presence of the sensitized placenta. Evidently we 

 have here complete parallelism between this phenomenon and 

 that of sensitization of erythrocytes by an active hemolytic 

 serum. 



In studying the complement activity of a pregnant individual's 

 serum exhausted of its specific elements by the above method, it 

 was found that the complement tends to deteriorate very rapidly, 

 much more rapidly than in the male serum treated in an exactly 



