104 Transactions OF the Canadian Institute. [Vol. V'II. 



forming alkaline nitrogenous compounds of simple composition. Of 

 the remaining two ferments, one was a vibrio, which preferred an 

 optimum temperature of 75 to 80 F., formed spores, and caused ihe 

 development of carbonic acid and hydrogen gas when grown in milk. 

 The casein was transformed into an albuminous substance, soluble in 

 water ; small amounts of butyric acid and sodium butyrate were 

 formed. 



Duclaux attributed the matting together of the cheese after it was 

 cut, to the action of this vibrio, which he thought caused the parts of 

 the coagulum to stick together and form a solid mass of cheese ; 

 consequently the presence of this germ was desirable, but unfortunately 

 should the germ enter the coagulum itself gas was produced ; and, as a 

 consequence, the cheese became puffy or swollen. 



The other ferment was more objectionable because it formed acetic 

 acid, and a substance of an intensely bitter taste. 



In conclusion, he considered the ripening to be caused by the 

 butyric ferment, because under its influence the casein was precipitated, 

 but afterwards graduall}- dissolved or digested. This ferment was 

 probably helped by others which acted upon the albuminoids so as to 

 split them up into compounds of a less complex nature; ammonia being 

 the simplest. 



Benecke made a microscopical analysis of Emmenthaler cheese of 

 different ages. He found Cohn's rod-like bacteria, which were probably 

 identical with B. subtilis, and also yeasts. In consideration of the 

 circumstance that the formation of peptone like bodies took place 

 chiefly at the beginning of the ripening process, and that at this time an 

 increase of schizomycetes, probably identical with B. subtilis, was 

 noticed, Benecke arrived at the conclusion that the ferment which 

 brought about the peptonization of the fresh curd was B. subtilis. The 

 objection that B. subtilis was an aerobe and could not live in the interior 

 of hard cheese, he set aside and followed the observation of Liborius, 

 according to which B. subtilis retained its peptonizing qualities even 

 though the air was shut off, provided that some kind of sugar was 

 available. The gradual disappearance of the milk sugar was account- 

 able for the diminishing of the rod-like forms in cheese which had 

 reached a more advanced stage of ripeness. In conclusion, Benecke 

 believed that the formation of amides (Leucin, etc.) was not due to the 

 action of the Schizomycetes. 



In 1887, Duclaux published the results of further studies upon 



