METHODS OF EXAMINING MILK 



233 



DETERMINATION OF THE PER CENT. OF FAT 



Babcock Test. The method devised by Dr. S. M. 

 Babcock is the one most commonly used in the United 

 States for determining the per cent, of fat in milk and 

 other dairy products. The apparatus required consists 

 of a bottle of about 50 c.c. capacity with a long neck 

 containing graduations from which the per cent, of fat 

 can be read off, a pipette holding 17.6 c.c., and a small 

 measuring cylinder graduated to measure 17.5 c.c. A 

 centrifuge is also necessary. The graduations on the 

 neck of the old type of bottle extend from to 10 per 

 cent., with subdivisions of 0.2 per cent., but on the more 

 recent type the scale is divided into tenths and extends 

 from to 8 per cent. Only glassware should be used 

 which has been tested and approved by the United States 

 Bureau of Standards. Commercial sulphuric acid with 

 a specific gravity of 1.82 to 1.83 at 60 F. is used in 



