THE BIOCHEMICAL SOCIETY, ENGLAND. 



Proceedings Reported by R. H. A. Flimmer^ Secretary 



I. HONORARY SECRETARY'S ANNOUNCEMENT OF THE SCIEN- 

 TIFIC PURPOSE AND SCORE OF THE MEETING 

 ON MAY 5, 1915^ 



The Meeting is to be devoted to a discussion of " Methods 

 adopted in the estimation of the nitrogenous constituents of extracts 

 derived f rom albuminous substances such as meat extracts and simi- 

 lar products, with special reference to the interpretation of the 

 results." 



The following scheme, which represents the chemical methods 

 commonly made use of in the examination of nitrogenous extracts, is 

 intended to serve as the basis of discussion : 



Meat Fibre and Coagulable Albumenoids. Ten (10) 

 grammes of the extract are dissolved in 100 c.c. of cold water. Five 

 (5) drops of acetic acid are added and the Solution brought to the 

 boil and allowed to boil gently for 5 minutes. It is then filtered and 

 the precipitate is washed with warm water, and the nitrogen de- 

 termined by Kjeldahl's method in the ordinary way. N X 6.25 = 

 Meat fibre and coagulable albumenoids. 



Albumoses and Peptones. The filtrate from the meat fibre 

 and coagulable albumenoids is made up to a definite volume and an 

 amount corresponding with 5 grammes of the original extract 

 pipetted out. To this is added a few drops of hydrochloric acid and 

 then bromine water in large excess. The precipitate is then collected 

 in tubes by means of a centrifugal machine, washed with bromine 

 water in the same way, dissolved in hot water, and Kjeldahled. 



N X 6.25 = Albumoses and peptones. 



Some analysts are in the habit of saturating the filtrate from the 

 coagulable albumenoids with zinc sulphate for the purpose of pre- 

 cipitating the albumoses. In that case the nitrogen so obtained is 



iThe last previous meeting was held March 11. See Biochemical Bul- 

 letin, 1915, iv, p. 174. 



414 



