72 



Testing Milk and Its Products. 



ratus used in this test. When the directions for operating, the 

 test are followed closely, the results obtained are accurate and 

 very satisfactory 



83. Barllett's modification. Bartlett 1 proposed a modifi- 

 cation of the method of procedure in the Babcock test, which 



aims to simplify the manipulations. 20 

 cc. of acid are added, instead of 17.5 

 cc., and the bottles filled with the milk- 

 acid mixture are left standing for not 

 less than five minutes and then filled 

 with hot water to within the scale; the 

 bottles are then whirled for five min- 

 utes at the regular rate (52). 



83a Siegfeld's modification. The 

 German dairy chemist Siegfeld in 

 1899 proposed a modification of the 

 Babcock test (MolTcerei Ztg. 1899, p. 



O51) using 2 cc. of amyl alcohol with 

 the sulfuric acid, and filling up with 

 dilute sulfuric acid (1:1, sp. gr. 1.5) 



in one filling, in place of water after 



the whirling. A clear separation of the 

 fat is facilitated by both these changes, 

 but when properly conducted there is 

 no difficulty whatever in obtaining a 

 clear fat column in the Babcock test as Pipette used 

 described in this book, and the modifica- ^an^es/^'^ 

 tion will not therefore be likely to be 

 FIG. 27. generally introduced in American factories. It has, 

 used 8 in the however, been adopted in many German creameries 

 Russian test. w h ere the Babcock test is used. 



84. Bausch and Lomb centrifuge. Fig. 29 shows a form of 

 hand centrifuge which may be used to advantage by physicians 

 of in pathological laboratories for the determination of fat in 

 milk. The centrifuge is especially designed for examination of 

 urine, sputum, blood, etc., but has been adapted to milk analysis 

 by the Leflfmann & Beam test, a special form of bottle (fig. 30) 





X 



FIG. 28. 



Maine experiment station, bull. 81 (H. *.). 



