VEGETABLE OILS. 



167 



called amygdalin (G^^ B^ NOu), on which it acts in a peculiar manner, 

 producing hydrocyanic acid. IHastase is an azotised substance procured 

 from malt, and developed during the germination of plants. It is 

 probably fibrin in an altered state, and it has the power of promoting 

 the conversion of starch into sugar. 



The azotised products of plants have a composition similar to blood 

 and muscular fibre, and hence their value in the food of man and 

 animals. The following table gives a general view of the quantity of 

 azotised and unazotised matters occurring in certain plants, with the 

 amount of water and inorganic matter : — 



Azotised Carbonaceous 



The following arrangement is given by Fromberg of the compara- 

 tive value of various plants as articles of food, taking into account the 

 protein compounds, and the starch, gum, and saccharine matter which 

 they contain, the highest value being 100 : — 



As regards the produce of different crops per acre, Johnston- gives 

 the following estimate of the nutritive products which they yield : — 



Average produce per No. of Iba, of true 



acre of tubers and nutriment in pro- 



grain, duce of an acre. 



Beet, Mangel-wurzel, and Turnip 30 tons . . . 672 lbs. 



Beans .... 30 bushels, or 1980 lbs. 594 ,, 



8 tons ... 358 „ 



20 bushels, or 1160 lbs. 348 „ 



36 bushels, or 1872 lbs. 243 „ 



10 tons ... 224 „ 



25 bushels, or 1500 lbs. 180 ,, 



30 bushels, or 1200 lbs. 132 „ 



Potatoes 



Peas 



Barley 



Jerusalem Artichokes 



Wheat 



Oats . 



Fixed Oils are found in the cells and intercellular spaces of the 

 fruit, leaves, and other parts of plants. Some of these are drying oils, 

 as Linseed oil, from Linum usitatissimum ; others are fat oils, as that 

 from Olives (fruit of Olea europsea); while others are concrete, as 

 Palm oil. The solid oils or fats procured from plants, are Butter of 



