PHYSICAL AND CHEMICAL EXAMINATION OF MILK 137 



When the container is large, as the common shipping can, 

 for example, a fair sample can be obtained by the use of milk 

 samplers. The "Scovell sampling tube" is an instrument de- 

 signed for this purpose (Fig. 29). This sampler is made of cop- 

 per or brass and consists of two cyhnders which telescope together. 

 The lower small cyUnder has several oblong apertures and the 

 upper long cylinder fits tightly into the small one. The sampler 

 is lowered into the can until it reaches the bottom, and after it is 

 filled with milk the upper cylinder is pushed down, thus closing 



Fig. 28. — Combined cream stirrer and 

 sampler (Van Slyke). 



Fig. 29. — Scovell sampler. 



the holes of the lower cylinder. The sample contains some milk 

 from each layer of milk in the can and the contents fairly repre- 

 sent the whole amount of milk. The sample is poured into a 

 small vessel and poured back and forth from this vessel to another 

 until it is thoroughly mixed. 



The McKay is another type of sampler. It consists of two 

 tubes, each with a handle and one fitting inside the other. A 

 turn of the handles opens or closes the sampler. Each tube has 

 several slots on the side. The sample is taken after the sampler 

 has been lowered to the bottom of the can and opened by a turn 



