THE FORMATION OF OILS IN PLANTS 143 



18 to 30 per cent., with a corresponding reduction in the 

 other constituents. The resulting cake is highly esteemed 

 as a cattle food, being of a very palatable nature. 



Rape Seed (Colza, Sarson). — Rape seed is grown in 

 European countries and also very largely in India. The 

 bulk of the Bast Indian seed is imported from Calcutta, 

 Madras, and Bombay, the large-growing districts being in 

 Guzerat and Ferozepore. Rape seed contains about 33 

 to 43 per cent, of oil, 22 to 27 per cent, albuminoids, and 4 

 per cent, fibre, the French seed being the richest in oil. 

 It is crushed between rollers in the same way as the other 

 oil seeds. The crude oil is dark coloured, and generally needs 

 to be refined by treating at the ordinary temperature with 

 about I per cent, strong sulphuric acid. The cold-drawn 

 oil is used in India as an edible oil. The oil is also used for 

 lubricating purposes, and for the manufacture of soap. 

 The cakes obtained after pressing the oil are of somewhat 

 doubtful utility for feeding cattle. Rape seed often contains 

 materials which develop a mustard oil after hydrolysis 

 by an enzyme. The amount of proper enzyme in rape is 

 commonly deficient, but the admixture of mustard seed 

 provides the necessary enzyme for developing the mustard 

 oil. The problem is, therefore, parallel to the development 

 of prussic acid in linseed. When the cakes are perfectly 

 pure, and free from mustard seed, and have not become 

 acted upon by heat and moisture, the material may be 

 fed with safety, but there is always the risk that either 

 insufficient cleaning in manufacture, or improper s^'stems 

 of feeding the cattle, may give rise to the development of 

 mustard oil, which is pungent and irritating to the animals, 

 and has been reported to have actually caused death. 



Safflower Seed. — This plant has been grown in India 

 to a large extent, originally for the preparation of saffron 

 dye, but the seeds are also pressed for their oil. They are 

 rich in oil, containing 30 to 35 per cent., but, owing to the 

 very thick, springy husk, great difficulty occurs in expressing 

 the oil, but the oil is prepared in India on a small scale for 

 local purposes, being largely used for human consumption. 



