130 COMPOSITE SAMPLES 



jar when a sample is added to it to mix the cream, which rises to 

 some extent after the milk has stood a while. 



Average Sample. It is sometimes desirable to obtain an 

 average test of the milk from a whole day's delivery. This can 

 be obtained in two ways: First, by taking a sample from each 

 patron's milk with a sampling- tube, and putting all the samples 

 together in one jar. The result represents an average test, pro- 

 viding the samples have been correctly taken. Second an aver- 

 age test can be had by boring a small hole in the conductor-head. 

 When the milk passes over this hole, a small portion of it drops 

 through. A vessel of some kind can be put underneath to catch 

 the drops. Such a drip-sample will represent very accurately 

 the average quality of the milk received at the creamery. If it is 

 desirable to keep this sample, a preservative can be added to it. 



Composite Sampling without the Use of Preservatives. 

 Pipettes can be obtained holding 5.87 c.c. of milk. These are 

 one-third the size of the ordinary 17.6 c.c. pipette used for the 

 Babcock test. With this small pipette a sample may be taken 

 every day from each patron's milk, during three successive days, 

 and emptied into the same test-bottle each day. At the end of 

 three days the samples may be tested and the bottles cleaned, 

 ready for use again. 



Accurate composite samples may be obtained in this way, 

 providing the sample in the pipette is correctly taken each day. 

 No preservative is needed. The preservatives are added to the 

 composite samples to prevent curdling. The test-bottles may 

 be placed on a shelf, or preferably in a rack made to hold them. 

 They should be marked in such a way as to identify them. 

 A good way is to mark them as the composite jars are marked, 

 the number on the test-bottle corresponding to the number on 

 the milk-sheet for each patron. 



