90 The Feeding of Animals 



oil. The average percentages in these seeds and nuts 

 are approximately as given below: 



Oil in certain seeds 



Per cent Per cent 



Linseed 34 Peanuts 46 



Cottonseed 30 Cocoanuts 67 



Sunflower seed 32 Palm nuts 49 



Rape seed 42 Poppy seed 41 



Mustard seed 32 



The oils from all the above are important commer- 

 cial products, being used in a great variety of ways 

 in human foods and in the arts. In many cases, the 

 refuse from this extraction goes back to the farm as 

 food for the cattle. This is especially true of linseed 

 and cottonseed. 



The vegetable and animal fats and oils may, for 

 convenience' sake, be discussed in two divisions, the 

 neutral fats or glycerides and the fatty acids. The neutral 

 fats are combinations of the fatty acids with glycerine. 

 When, for instance, lard is treated at a high tempera- 

 ture with the alkalies, potash and soda, glycerine is 

 set free and an alkali takes its place in a union with 

 the fatty acids. This is the chemical change which 

 occurs in soap -making. There are several of these neu- 

 tral fats, the ones most prominent and important in 

 agriculture being those abundant in butter and in the 

 body fats of animals; viz., butyrin, caproin, caprylin, 

 caprin, laurin, myristin, olein, palmatin, and stearin. 

 Butyrin is a combination of butyric acid and glycer- 

 ine, stearin of stearic acid and glycerine, and so on. 



These individual fats possess greatly unlike physical 



