MAKING THE TEST: DRAWING SAMPLE 



309 



eyes and carefully release the forefinger, allowing air to enter 

 until the milk has descended exactly to the scratch on the stem 

 of the pipette. Again close tightly with the finger and transfer 

 the measured quantity to the test bottle. If the stem of the 

 pipette is sufficiently small, insert into the neck of the test bottle 

 (Fig. 1056) ; if not, hold the bottle and pipette at an angle, as 

 shown at figure 105. This is done to allow the milk to flow 



Fig. 105. — Filling milk test bottles. In a the bottle and pipette are being well 

 handled where it is necessary to hold them while the pipette is being emptied, b shows a 

 preferable method of emptying the pipette. When the tip of the pipette is slender enough 

 to enter the neck of the bottle, a disc of rubber packing or cork may be slipped on it and 

 the pipette allowed to drain by itself. Two or three such pipettes may be used in rotation. 



down the bottom side of the neck of the bottle, while permitting 

 air to escape on the upper side. The last drop of milk should be 

 saved by blowing it into the test bottle. 



In testing a number of samples care should be taken to rinse 

 the pipette once by drawing the milk of the next sample to be 

 tested into the pipette and blowing it back ; otherwise the quan- 

 tity of fat which sticks to the inside of the pipette goes from 



