i68 Proccedings Columbia Biochemical Association [Sept. 



reaction seems far more complicated than that caused by the phys- 

 ical or chemical procedures. The supernatant fluid from the fixa- 

 tion test differs from all the other end-pieces prepared by chemical 

 methods in being active upoii persensitized sheep corpuscles only 

 (not upon human corpuscles). The addition of various mid-pieces, 

 obtained by different methods, to sensitized sheep corpuscles does 

 not render the Wassermann supernatant fluid active. It is quite 

 remarkable that the persensitized sheep corpuscles are, on the other 

 hand, easily attacked, not only by the supernatant fluids of fixation 

 tests, but also equally well by the other end-pieces. It is not at all 

 improbable that in the fixation reaction, where so many factors come 

 into play, there is a most complicated physical as well as chemical 

 interaction leading to such an entangled mixture of factors that a 

 substance carrying one set of ions alone cannot reverse the activity 

 of complement, and hence the reversion takes place only when cer- 

 tain electrolytes with both ions are employed. At all events there 

 seems to be no doubt that the inactivation of complement is far 

 more complicated in the Wassermann reaction or the Bordet-Gen- 

 gou phenomenon than in the inactivation by physical or chemical 

 means. Nevertheless, no one has as yet proved conclusively that 

 the supernatant fluid of a fixation test necessarily contains the end- 

 piece of complement. 



i8. Notes on the chemical nature of Lloyd's " tannin 

 mass." Ernest D. Clark. Chemical studies were made upon 

 "tannin masses" prepared by Lloyd from the fruit of the persim- 

 mon. The original material dissolved in alkalies to form a purple 

 jelly-like Solution. In dilute mineral acid Solutions the "masses" 

 turned bright red in color and no swelling was observed. Upon 

 hydrolysis with 0.2 per cent. and 2.0 per cent. hydrochloric acid 

 Solutions, cherry-red colorations were obtained. Such Solutions 

 contained both tannin and phloroglucin in considerable proportions. 

 The presence of phenolic substances like vanillin was also indicated. 

 An insoluble gelatinous substance was removed, by filtration, from 

 the hydrolyzed acid mixture and seemed to be cellulose or a related 

 material. Hydrolysis with 0.5 per cent. and 5.0 per cent. sodium 

 hydroxid Solutions gave thick, dark-colored liquids and large 

 amounts of insoluble gelatinous residue. Alkaline hydrolysis pro- 



