COMPOSITION OF CHEESE. 339 



ments." He finds that formalin or a temperature of 75 

 weakens the action of galactase. 



Duclaux, as long ago as 18801, ascribed the ripening of cheese 

 to changes in the casein produced by enzymes, but the latter 

 were thought by him to be produced by the life-processes of 

 micro-organisms. It seems probable that this view is also 

 true so far as some of the changes in cheese are concerned. 



The following are analyses of several varieties of cheese 

 quoted by Wiley]:: 



Water. Casein. Fat. Sugar. Ash. 



The above analyses are of the type usually made, but are 

 not satisfactory, inasmuch as they do not differentiate between 

 the various nitrogenous compounds present, some of which 

 are almost valueless as food. Eecently attempts have been 

 made to get more detailed results. As an example, Stutzer 

 gives the results of his investigation of the nitrogenous con- 

 stituents of Camembert and of Swiss cheeses as follows ; the 

 total nitrogen in each was distributed thus : 



Camembert. Swiss. 

 % % 



.Nitrogen as ammonia ... 13'0 3*7 



,, amides ... ... 38'5 9-0 



,, ,, albumoses, peptones 30'5 8'6 



,, indigestible ... ... 4*0 2'4 



,, as casein, albumin ... 14-0 76'3 



In the Camembert the ripening process had proceeded very 

 far, while the Swiss cheese was comparatively fresh. 



* Jour Chem. Soc. 1900, abst. ii. 712. t Jour. Chem. Soc. 1882, 436. 



t Agricultural Analysis, Vol III. 524. 

 Stutzer, Jour. Chem. Soc. 1896, abst. ii. 683. 



z2 



