8o Biological Scction, American Chemical Society [Oct. 



the higher animals and its application to medicine ; the biochemistry 

 of the lower animals ; and biochemistry in its appHcation to plants, 

 agricuhure, and the industries. 



Carl L. Alsberg, Chairman 



Bureau of Chemisiry, 



U. S. Department of Agriculture, 

 Washington, D. C. 



III. SCIENTIFIC PROCEEDINGS (ABSTRACTS) 

 On the presence of histidine-like substances in the pituitary 

 gland (posterior lobe). T. B. Aldrich. (Research Laboratory 

 of Parke, Davis & Co., Detroit, Mich.) Employing Pauly's dia- 

 zobenzene sulphonic acid reaction for the detection of histidine, it 

 seems probable that histidine or some form of it is contained in a 

 free State in the desiccated posterior lobe of the pituitary gland since, 

 by benzoylating direct, using Inouye's method, Pauly's reaction was 

 positive. The substance (or substances) giving Pauly's reaction, 

 after hydrolysis by means of mineral acids or digestion with pan- 

 creatin, is not tyrosine (which gives a similar reaction) since, after 

 benzoylating, the histidine reaction still persists. Furthermore, the 

 histidine-like substance (or substances) is probably not histidine, 

 since it does not give Weidel's reaction as modified by Fischer, or 

 Knopp's reaction with bromine. It is probable, also, that Pauly's 

 reaction is not a specific reaction for histidine. 



The mutual action of pepsin and trypsin. J. H. Long. 

 (Northwestern University Medical School, Chicago.) The earlier 

 physiologists seem to have considered this a comparatively simple 

 question, but their findings were not in agreement. Kühne was one 

 of the first to discuss the problem and he concluded that pepsin 

 destroys trypsin. This is probably correct but his experimental 

 evidence does not Warrant the Statement. In all such experiments 

 the reaction of the medium must be definitely known as the concen- 

 tration of hydrogen or hydroxyl ions is often the determining factor. 

 In most of the earlier work these points were almost wholly over- 

 looked, as the combining power of protein for acid or alkali was 

 either not known or not recognized. Making due allowance for the 

 reaction of the medium, the present experiments show that, within 

 the practical limits of behavior in the body, trypsin has no important 



