SAMPLING OF MILK 119 



the use of a suitable sampling tube is much better. It takes a 

 more representative sample of a can of cream, whether it be for 

 the making up of a composite sample or for the testing of an 

 individual shipment. In the case of composite samples of both 

 milk and cream it takes an aliquot portion, or one in proportion 

 to the quantity of milk or cream delivered. The difficulty at 

 one time in sampling cream and particularly thick cream 

 with the sampling tube was that the only opening in the tube 

 was at the bottom, and the cream would not flow into it as the 

 tube was lowered. However, this trouble is completely over- 

 come when a sampler like the McKay sampler is used. This is 

 made up of two tubes, an inner and an outer, and a plunger 

 (see cut). Both the tubes have openings up the side. Before 

 inserting the sampler in a can of cream, the outer tube is turned 

 on the inner so that the openings are not opposite each other, or 

 so as to close the sampler, and the plunger is drawn back. The 

 sampler is then lowered into the cream to the bottom of the can, 

 when it is opened momentarily to allow it to fill and is then closed 

 again. In emptying the sampler the outer tube, which is the 

 shorter of the two, is drawn up a little to leave an opening at the 

 bottom, and the plunger is pushed down to force the cream out of 

 the tube. In doing so it cleans the tube completely. This style 

 of sampler does equally efficient work whether used in a 

 creamery or cream station, or in taking samples on a cream 

 route. 



An investigation made by the American Association of Cream- 

 ery Butter Manufacturers showed the dipper method of sampling 

 cream to be unreliable. In this investigation the cream in the 

 can was first hand-stirred no less than forty vigorous double 

 strokes being used and then sampled with a dipper, after 

 which a sample was taken by means of a McKay or tube sampler. 

 In all, thirty-two lots of cream were sampled and tested in this 

 way, and the following short table gives some of the results 

 secured : 



