MODERN METHODS OF TESTING MILK 



four of which can be placed in the oven at the same 

 time. The samples are heated until the residue appears 

 brown, which takes from 30 to 60 minutes, depending 

 on the amount of the sample and the temperature of 

 the oven. A lo-gram sample can be dried at 260 F. 

 in about 30 minutes; a 5o-gram sample requires at 

 least 60 minutes. It is a safe precaution to heat sam- 

 ples a second time to make sure that the water is com- 

 pletely evaporated, especially until one has had suffi- 



FIG. 370 FARRINGTON'S HIGH-PRESSURE OVEN 



