24 



Therefore in order to yield 1 pound butter per inch, 



lUiJ 



4.1 pounds cream must contain ^ pounds fat. 



100 



1 pound cream must contain ^^r- divided by 4.1 pounds fat 



I'OO pounds cream must contain 73^ X_ jy X -y- 



Equal to 21.2 pounds fat. 



According to experiments conducted at the Ontario Agricultural 

 College Dairy School, the actual percentage of fat in Cieam yielding 1 

 pound of butter per inch is 21.1 per cent. 



The relation between the value of a pound of fat and a pound of 

 butter may be found to vary somewhat according to the percentage of 

 overrun obtained. 



With an average overrun of 15 per cent. ,and butter worth 17 

 cents per pound, the value of a pound of fat may be estimated as fol- 

 lows : A 15 per cent, overrun would prove 100 pounds fat to yield 

 115 pounds butter; 115 pounds butter at 17 cents equals $19.55; then 

 100 pounds of fat must be of the same value — $19.55. Therefore, 1 

 pound fat must be worth 19.55 cents. If fat were worth 17 cents a 

 pound, the value of 1 pound could be estimated as follows : 



100 pounds fat at 17 cents equals $17-00. 



100 pounds fat should yield about 115 pounds butter, therefore, 



115 pounds butter are worth $17.00. 



1 pound butter is worth $17-^11-^ equals 14.78 cents. » 



With an average overrun and butter worth from 16 to 18 cents 

 per pound the difference between the value of a pound of fat and a 

 pound of butter would be from 2 to 2^ cents per pound. 



Skim-Milk Buttermilk, and Whey. 



As the percentage of fat in skim milk, butter-milk, and whey is 

 so small, the best method of testing these is by the use of the double- 

 neck skim-milk bottle. 



The usual amount of milk or whey is taken and the test is made 

 in the usual way. Very fine readings can be taken, as a very small 

 amount of fat will extend over quite a length in the small neck. Con- 

 siderable controversy has taken place from time to time among the 

 leading authorities as to how each division on the scale should be read, 

 but it has been demonstrated that reading the first divisions as .1 (^q-) 

 and each succeeding division as .0-5 (>2 of -,y- equals ^p- or .05) gives 

 results comparing quite favorably with gravimetric analysis. 



Slightly more than 17.5 c.c. of acid may be used to advantage when 

 testing skim-milk ; it is also advisable to increase the speed of the tes- 

 ter or the length of time it is whirled. 



The fat column in a double-necked bottle may be raised to any de- 

 sired point on the scale by gently- pressing with the finger on the mouth 

 of the large neck, 



