[macfablane] on the ANALYSIS OF CHEESE 13 



From Table III. it \yill be observed that the percentage of nitrogen 

 in the organic substance of the alcohol extract varies from 6.81 to 9.46, 

 showing again a much lower percentage than casein. As regards the 

 nature of this substance it is difficult to come to a conclusion concerning 

 it. ÎSTearly all proteids have heretofore been regarded as insoluble in 

 alcohol. In Wroblewski's classification of these (The Analyst XXIII, 

 p. 107), there is certainly mention made under his Group I of a sub- 

 division of " albuminous substances soluble in alcohol," but these are 

 chiefly of vegetable origin, a prominent example being gliadin, one of 

 the constituents of gluten. Casein itself is classed as a compound pro- 

 teid or nucleo-albumin. The nitrogen percentage in the organic matter 

 of the aqueous extract is higher than that of the alcohol extract, but 

 lower than casein, and the substance would seem to be capable of classi- 

 fication among the peptones. Further investigation is required in order 

 to ascertain the true composition and nature of the substances con- 

 tained in these extracts. 



