340 STATE BOARD OP AGRICULTURE. 



Taking Samples. — 



Great care should be exercised that the small samples taken are an 

 accurate and an aliquot part of the whole. To be so the milk should 

 be thoroughly mixed and some device should be used in taking the 

 sample that will take a corresponding part of the whole each day. If 

 the quantity of milk varies but little from day to day, a half ounce dipper 

 can be used to advantage, but where there is a considerable variation 

 in the quantity, a sampling tube is much more accurate. 



The sampling tube, of which there are many styles, consists principally 

 of a long, hollow, metal tube which is let down into the milk to the 

 bottom of the receptacle and when filled is drawn out. This gets a uni- 

 form proportion of the milk as it takes a sample corresponding to the 

 amount of milk in the receptacle and it also provides a strictly repre- 

 sentative sample of the milk, as it takes a uniform amount from each 

 lajer. 



Preservatives Used. — 



The following preservatives have been found best to use in composite 

 sampling : — 



1. Corrosive sublimate. 



2. Formalin and 



3. Potassium bichromate. 



Corrosive sublimate is the most satisfactory for general use, being a 

 more powerful antiseptic than either of the others. It is put up in 

 tablet form and being deadly poison, it is colored pink, which warns 

 people against using any of the milk in which it is put. One tablet 

 will preserve one pint of milk at least two weeks in warm weather. 



Care of Composite Samples. — 



1. Composite samples should be kept covered tightly to prevent 

 evaporation of water which would tend to make the fat test higher than 

 it normally should be. Also, the evaporation may cause the formation 

 of a tough cream, rendering difficult the taking of a good sample for 

 testing. 



2. The containing jar should be shaken each time a sample is added, 

 otherwise cream will come to the surface and where it comes in contact 

 with the sides of the bottle, forms a tough layer, rendering sampling 

 difficult. 



3. The sample should be kept in as cool a place as possible, so that 

 no more preservative than is absolutely necessary need be used. 



When to Test.— 



Composite samples should not be carried along more than two weeks 

 without testing. If they are kept longer than this, it is nearly impossible 

 to get a perfectly reliable fat test. Patrons of a creamery where the 

 samples are tested only once a month have a legitimate right to object 

 to the results-. 



Testing Composite Samples. — 



When the composite sample is to be tested, it is treated according 

 to directions for testing whole milk. 



W. B. LIVERANCE, 

 Instructor in Dairying. 



