114 Transactions of the Canadian Institute. [Vol. V'II. 



proteids (albumoses and peptones) comparable to the breaking down of 

 the casein in the normal ripening of cheese. Bacterial life was not 

 absolutely excluded from the milk with which the experiments were 

 performed, but by elaborate precautions, their numbers were minimized 

 as much as possible. 



Cheese was also cured under anaesthetic conditions. A cheese 

 kept under chloroform and heavily saturated with this anaesthetic, even 

 when more than a year old was physically thoroughly broken down and 

 resembled a well cured cheese. Chemically, more than fifty per cent, of 

 the casein was converted into soluble products, which amount is about 

 the same as that found in normal cheese of the same age. Bacteriologi- 

 cally it was sterile. 



These experiments seemed to the authors to indicate that the 

 inherent enzymes in the milk pla}ed a very important role in the break- 

 down of the casein. 



The year following this discovery, 1897, the authors published 

 additional studies, and named the ferment galactase, on account of its 

 presence in milk. It was found that this enzyme was allied to trypsin, 

 the digestive ferment of the pancreas, and in this connection, it is inter- 

 esting to note that Jensen independently discovered that cheese made 

 from pasteurised milk with the addition of ether to prevent bacterial 

 action, and a certain amount of pancreas to furnish the tr}-psin, cured 

 more quickly, and contained nearly fifty per cent, more soluble nitrogen 

 than cheese made without the addition of pancreas. 



This ferment, however, differs from trypsin, in that it gives rise to a 

 certain amount of free ammonia. It also differs with regard to the 

 temperature at which its action is most energetic. 



Storch's test for determining whether milk has been heated to a 

 temperature exceeding 80° C. depends on the presence of galactase, the 

 activity of which is destro\-ed by this temperature. 



Babcock and Russell also made extensive researches on the distribu- 

 tion of galactase in different species of mammalia, in individual milks at 

 the same or different periods of lactation, etc. 



As to the structures in the body in which the enz\-me is found, the 

 authors have not \'et examined the mammary glands for its presence, 

 but suggested the close relationship between the blood and milk, as seen 

 in the production of immunizing substances in the milk of animals 

 rendered artificial!}- immune to bacterial poisons. 



