52 



DAinr CHEMISTRY 



is similar to the Babcock test bottle, except that it is 

 provided with a bulb in the steni to accommodate 

 the additional fat from the cream. In using this 

 bottle, care should be exercised that the right 



amount of water is added 



so as to leave a sufficient 

 amount of fat both above 

 and below the bulb for the 

 purpose of reading. The 

 Winton test bottle is pro- 

 vided with a larger gradu- 

 ated neck than the ordinary 

 test bottle. 



In the testing of cream 

 greater care is necessary 

 than in the testing of milk. 

 When cream is measured 

 with the pipette, an error 

 is introduced into the work 

 because cream has a lower 

 specific gravity than milk. 

 17.6 cc. of cream testing 

 25 per cent fat weighs Fm.is.— Bart- 

 only about 17.2 gm. 

 Since the test bottles are 

 made for 18 gm. of milk, the results are neces- 

 sarily low when applied to cream. Farrington and 

 WoU, in " Testing Milk and Its Products," give the 

 weight of cream delivered by a 17.6 cc. pipette as 

 follows : — 



,( 



Fig. 14. — Win- 

 ton cream test 

 bottle. 



lett cream 

 test bottle. 



