458 Proceedings Columbia Biochemical Association [April-July 



antigen of the tuberculin, is a question to be decided by the experi- 

 ments which are to follow. 



At present I wish to call attention to this phenomenon as a pos- 

 sible method for the diagnosis of tuberculosis, at least in cases 

 where the condition is not too far advanced and where there is some 

 of the free antibody in the circulating blood. 



Subcutaneous injection (0.05 cc.) of a mixture of fresh blood 

 of patients suffering from tuberculosis (i cc.) with tuberculin 

 (crude, dil. i to 10; o.i cc.) into a normal guinea pig causes a local 

 reaction similar in its aspect to a tuberculin reaction, which is of 

 good prognostic value for the diagnosis of tuberculosis. 



B. ABSTRACTS OF PAPERS FROM THE COLUMBIA BIOCHEMICAL 

 DEPARTMENT AND AFFILIATED LABORATORIES 



122. Acetone as a precipitant of albumin. Mark J. Gott- 

 lieb. In searching for a reagent which would precipitate egg 

 white and yet not denature it, the f ollowing f act was established re- 

 garding the action of acetone : A conc. of acetone above 50 

 percent is necessary for the complete precipitation of protein 

 from a IG percent sol. of ^gg white in 5 percent sodium chlorid sol. 

 The protein is denatured by the acetone in any conc, and the precip- 

 itate is entirely insoluble in water or salt sol. 



123. A biochemical study of certain bacterial pigments.® 

 I. J. Kligler, Excepting the fluorescent pigment produced by B. 

 pyocyaneus and B. fluorescens, which has been thoroughly investi- 

 gated by Gessard, Thume, Jordan and others, little work has been 

 done on the nature of bacterial pigments. This is probably due 

 largely to the prevailing idea that the production of pigments by 

 bacteria is an easily suppressible function and of little specific impor- 

 tance. Schneider showed, however, that the extracted pigments of 

 a number of organisms studied by him reacted in a very definite 

 manner to various chemical reagents, such as solvents, acids, alka- 

 lies, etc. The Winslows called attention to the significance of the 

 color of the pigment produced as a differential character among the 

 cocci. They were able to show a striking correlation between the 

 type of pigment produced, and other biochemical and morphological 



«Conducted in part in the Biochem. Lab. of the Dep't of Public HeaUh, 

 Amer. Museum of Nat. Hist., N. Y. City. 



