THE ELEMENTS OF PLANT FOOD 39 



Olein (C^H^Ce) at ordinary temperatures is a liquid. Sperm oil 

 and cod liver oil are rich in olein. Fats that are soft or have a tendency 

 to become liquid under normal conditions owe their softness to the 

 presence of olein. 



Butyrin is the fat that gives to butter its characteristic taste when 

 fresh. In strong, or rancid, butter some of the butyrin has changed 

 to butyric acid, which produces the unpleasant flavor and odor. By 

 thoroughly washing, this acid may be washed out of the butter, and 

 then by reworking, the butter may be made more palatable. Reno- 

 vated butter is made by thoroughly washing strong or rancid butter, 

 melting it, blowing hot air throught it, filtering it, and then rechurning it 

 with sweet milk. 



Oleomargarine, or butterine, is made largely from stearin. Beef 

 suet or tallow is melted, and a clear yellow oil is obtained. This oil is 

 allowed to become solid and pressure is applied to it, forcing out an oil 

 which, when mixed with lard and cottonseed oil and churned with 

 milk, produces a wholesome food product somewhat resembling butter. 



Ether Extract. This is a term used to indicate sub- 

 stances that are dissolved by ether. In food tables 

 when the term ether extract is used it includes all 

 fats. Ether will dissolve fats, oils, gums, resins, and 

 chlorophyll. The largest amount of ether extract 

 of both vegetable and animal matter is fats and 

 oils. 



Saponification, or Soap Making. When an al- 

 kali acts upon a fat or oil, a soap is produced. A tea- 

 spoonful of ammonia in a glass of water will make a 

 wash for the scalp. When the scalp is rubbed with 

 this alkali, saponification takes place. The oil in the 

 scalp combines with the ammonia, and a soap is formed 

 which works up into a lather in the hair. Caustic 

 soda and potash are the alkalies commonly used to 

 make soap, soft soap being made from caustic potash 

 and hard soap being made from caustic soda. Soft soap 



