98 GUIDE TO DAIRYING IN SOUTH AFRICA 



equal to 17*5 c.c. by measure. But as some of the 

 milk will adhere to the pipette by which it is 

 measured, we use a pipette to hold 17 '6 c.c. to 

 ensure that exactly 17-5 c.c. will be delivered 

 into the milk-test bottle. We therefore stir the 

 milk well which is to be tested, and draw; it up into 

 the glass pipette, provided with the apparatus, 

 by means of suction from the mouth until the 

 column of milk rises in it above the 17*6 c.c. 

 mark on the glass. Next slip the first finger 

 of the right hand over the top of the pipette on 

 the instant of removing one's mouth this is to 

 prevent the milk column from running out ; holding 

 the pipette between the thumb and middle finger of 

 the right hand, this is easily accomplished. We 

 now have the milk above the 17*6 c.c. mark, and 

 by raising the first finger ever so slightly and allow- 

 ing a little air into the pipette the column of milk 

 will gradually drop. When the top of the milk 

 column has exactly reached the mark the finger 

 may be pressed down tightly to prevent the milk 

 going any lower. A little practice will soon enable 

 one to do this perfectly. Having now obtained the 

 required amount of milk 17*6 c.c. to be tested, this 

 may be run into the milk-test bottle by placing the 

 end of pipette in the neck of the milk-test bottle, 

 and removing the finger from the top and allowing 

 all the milk to run into the bottle. We now add 

 1 7 *5 c.c. of sulphuric acid. This should be measured, 

 and never drawn up by means of pipette r , for one may 



