EXPERIMENT STATION BULLETINS. 



333 



Test Bottles.— 



Test bottles of the same general style are used in testing whole milk, 

 skim-milk and cream. They differ, however, in the manner in which the 

 neck of the bottle is graduated. 



The neck of the whole milk test bottle is marked with a scale graduated 

 to read .2 (two-tenths of a per cent), five of these divisions making one 

 large division which represents one per cent 

 from to 10%. See ill. 3, fig. d. 



The graduation extends 



a 



c d 



Illustration 3. 



The neck of the cream test bottle most commonly used is about six 

 inches long, graduated from — 30%. The smallest divisions in this 

 graduation are half per cents. See ill. 3, fig. &. Some cream bottles, 

 however, are nine inches long and graduated to read quarter per cents, 

 which makes a more accurate reading. See ill. 3, fig. c. Figure a shows 

 a nine inch cream test bottle graduated to 50%, reading half per cents. 

 These bottles cannot always be used, because they are three inches longer 

 than the ordinary cream bottles and so require a special tester. 



Skim-milk, whey and buttermilk test bottles are made with double 

 necks. The milk and acid are delivered through the larger neck while 

 the smaller one is used for the per cent of fat. There are two methods 

 of graduation in skim-milk bottles, one reading to .01 per cent, see 

 ill. 3, fig. e, and the other to .05 per cent, see ill. 3, fig. f. 



Dividers. — 



The dividers shown above test bottles in ill. 3 are used for convenience 

 in measuring the fat colifmn. 



