172 Da try Bacteriology. 



bacteriological science, evidence was forthcoming that 

 seemed to indicate that the activity of organisms entered 

 into the problem. SchafFer 1 showed that if milk was boiled 

 and made into cheese, the casein failed to break down. 

 Adametz 2 added to green cheese various disinfectants, as 

 creolin and thymol, and found that this practically stopped 

 the curing process. From these experiments he drew the 

 conclusion that bacteria must be the cause of the change, 

 because these organisms were killed; but when it is con- 

 sidered that such treatment would also destroy the activity 

 of enzyms as well as vital ferments, it is evident that these 

 experiments were quite indecisive. 



A determination of the nature of the by-products found 

 in maturing cheese indicates that the general character of 

 the ripening change is a peptonization or digestion of the 

 casein. 



Until recently the most widely accepted views relating 

 to the cause of this change have been those which ascribed 

 the transformation to the activity of micro-organisms, 

 although concerning the nature of these organisms there 

 has been no unanimity of opinion. The overwhelming 

 development of bacteria in all cheeses naturally gave sup- 

 port to this view; and such experiments as detailed above 

 strengthened the idea that the casein transformation could 

 not occur where these ferment organisms were destroj'ed. 



The very nature of the changes produced in the casein 

 signified that to take part in this process any organism 

 must possess the property of dissolving the proteid mole- 

 cule, casein, and forming therefrom by-products that are 

 most generally found in other digestive or peptonizing 

 changes of this class. 



. 'Schaffer, Milch Zeit, 1889, p. 146. 

 'Adametz, Land w. Jahr., 18:261. 



