120 A New Davy Industry. 



steam is turned into the steam jacket and the tem- 

 perature brought up to 122° F., where it is kept 

 during the time necessary to remove the lump of 

 paracasein, which has' now formed on the bottom of 

 the vat, and which is effected by means of sieves fit- 

 ting snugly into the bottom of the vat. The 

 remaining whey will be found with agreeable, sweet 

 taste but must not retain any sediment of casein. 

 The vat is now heated- to 107° F. and kept at this 

 temperature for forty-five minutes to deaden the effect 

 of any ferment remaining, great care being required 

 not to exceed this temperature, or the albuminoids 

 will become indigestible. At this stage of proceed- 

 ings it is well to call to mind that no utensils or 

 vessels must now be dipped into the serum, or whey, 

 which previously have been used in fresh milk or 

 cream. After the elapse of the forty-five minutes of 

 heating, the serum is now- returned and mixed with 

 the cream previously separated from it, until it 

 appears as one homogenous fluid. Where condensing 

 is not applied to highten the percentage of milk sugar 

 this latter must now be added (five grammes per pound), 

 thoroughly mixed with the normal milk, which is at 

 once bottled and ready for the sterilzing apparatus. 



Before following this milk to sterilizing, we turn 

 to the manufacture of the second grade of normal 

 milk. The fresh milk is separated into one-third 

 part cream and two-thirds parts skim milk, the same 

 as for the first grade, and the calculation of fat per- 

 centage performed in the same manner. The casein 



