78 PLANT COMPOUNDS 



grade and is employed as a condiment. The oil expressed hot 

 from the original cake and from the seeds is less pure and is 

 used for lubricating purposes and soap making. The color 

 of the oil varies from a pale yellow to a greenish or brownish 

 shade. It contains about 72 per cent, olein and 28 per cent, 

 palmitin. Thin films dry slowly. Cotton seed oil is the 

 principal adulterant. 



(/) Peanut Oil is obtained from peanuts, and is a light 

 greenish-yellow oil, although colorless when refined. It is 

 used as an adulterant for olive oil, as a salad oil under 

 its own name, and for making butterine and soap. It con- 

 tains olein, linolein, palmitin, stearin, and some less known 

 glycerides. 



(g) Rapeseed Oil or Colza Oil is obtained from rapeseed 

 by hot pressing. The purified oil is light colored and used 

 as a condiment under the name of colza oil, rape seed oil 

 being applied to the darker colored oil which is used as a 

 lubricant and to some extent as a burning oil. Both kinds, 

 containing mostly olein, stearin, and brassin, are very 

 viscous, and on exposure to the air, become gummy, but 

 do not dry. 



(h) Sunflower Oil is obtained from the seeds of the 

 sunflower. It is pale yellow and of pleasant taste, being 

 used in cooking. Less pure grades are used for soap making 

 and as an adulterant for linseed oil, although it does not dry 

 as quickly. It is composed of olein, palmitin, and linolein 

 principally. 



70. Waxes. — These compounds are allied to the fixed 

 oils in that they have many of the properties of oils, and are 

 esters of fatty acids, but the acids are combined with mono- 

 hydric alcohols of high molecular weight, and not with 

 glycerine. In the plant they serve as a protective water- 

 proof coating on the stems, leaves, and fruit of many plants. 

 The "bloom" on plums is a wax. The surface of corn stalks 

 and sugar cane is covered with a thin layer of wax. The 

 waxes may be liquid or solid and are found in animals as 

 well as in plants. 



Carnauba Wax is the principal plant wax. It is a very 

 hard substance, usually of sulphur yellow color and obtained 



