Cream Testing. S3 



is built on the same principle as a lactometer : it is pro- 

 vided with a pan on the top of the stem, on which the 

 test bottles and the weights are placed. When put into 

 water the instrument is balanced to a certain point 

 with empty test bottles and weights on the pan; the 

 weights are then removed and sufficient cream added 

 to the test bottle by means of a pipette to sink it to 

 the same point as before. 



The special advantages of the balance are that there 

 are no bearings to rust and become dull; it is durable, 

 inexpensive and sensitive, and with careful handling 

 will remain sensitive indefinitely. The balance can be 

 made large enough to weigh a number of bottles at a 

 time, as is the case with some of the cream scales on 

 the market. 



92. Measuring cream for testing. Where a special 

 cream scale or a small balance is not available, fairly 

 satisfactory results may be obtained with cream of low 

 or average quality by measuring oiit the sample with 

 a 17.6 pipette and correcting the results as indicated 

 below. One of the cream test bottles or a common milk 

 test bottle may be used for this purpose. The table 

 ( n p. 77 shows that a 17.6 ee. pipette, in the case of 

 cream fresh from the separator, containing less than 

 25 per cent, of fat, will deliver only 17.2 grams of 

 cream, that is, the results will be 1^ ':^'=1.1 per cent, too 



' IS 



low. In the same way in case of 40 per cent, cream, 

 only 16.3 grams of cream would be delivered, and the 

 results therefore 3.8 per cent, too low. When the cream 

 has been ripened or is thick, less cream would be deliv- 

 ered than the amounts given, and the error introduced 

 by measuring out the samples correspondingly increased. 



