Measuring the Milk. 61 



composite samples, an amount proportionate to the 

 amount of milk delivered should be taken each day. 

 This is conveniently done by the use of the Scovell 

 Aliquot Milk Sampler, which, besides serving this 

 purpose, gives the advantages of a milk thief in that 

 it takes milk from all parts of the vessel. Where 

 the milk varies only a few pounds from day to 

 day, good results may be obtained by taking a uni- 

 form amount of milk for the sample each day, but 

 where the variation in quantity is considerable, 

 aliquot samplers are much to be preferred. 



Making the test. — In preparing to make the test, 

 the same care must be used that the sample shall 

 be thoroughly mixed and perfectly uniform, that 

 was taken in mixing the milk when the sample 

 was drawn. In measuring the milk, the pipette 

 should either be perfectly dry, or rinsed out with 

 the milk to be tested immediately before measur- 

 ing the assay. Where a large number of samples 

 are to be tested, the latter is found to be the better 

 practice. The greatest care should be taken that the 

 milk is accurately measured. The lower end of 

 the pipette should be placed about midway of the 

 sample of milk and the pipette filled bj^ gentle 

 suction at the upper end. The milk should be 

 drawn into the tube above the mark on the neck, 

 and the end of the forefinger quickly placed over 

 the end of the pipette, the pipette being steadied 

 by the thumb and second and third fingers ; hold- 

 ing it now on a level with the eye between the eye 

 and the light, the pressure on the forefinger 



