10-i LESSONS IN AGRICULTURE 



cream separator, in order to get the maximum amount 

 of cream and butter-fat that the herd produces, and 

 also a Babcock tester, to ascertain whether his cows are 

 yielding the highest percentage of butter-fat. A dis- 

 cussion of the Babock tester will follow in the practical 

 exercises. 



Practical Exercises 



NOTE. The practical exercises for this lesson follow 

 as separate lessons in the series. 



LESSON XXXI 



COMPOSITION OF MILK 



Learn the following facts about milk: 



M ilk consists of .about seven-eighths water and one- 

 eighth substances in solution in the water, or floating 

 in it in very small particles. You may be surprised 

 to learn that so large a proportion of milk is water. 

 This is true not only of milk but of many of our most 

 important foods. 



The constituents of milk are often referred to as 

 water and total solids; fat, casein, albumen, sugar, and 

 ash. A chemist can separate these substances with great 

 accuracy, but by the following methods we can make a 

 gross analysis: 



1. Leave a little milk in a saucer for a short time 

 in a warm place. The water will evaporate and leave 

 the solids in dry form. 



2. Separation of fat. Let a quart of fresh milk 

 quietly stand in a shallow pan, in a cool place, until 

 a layer of cream gathers at the top. This cream is 



