OIL SEEDS 51 



a second grinding before the hulls are sufficiently fine 

 for feeding purposes. This second grinding is done by 

 a pair of very heavy millstones, placed in a vertical 

 position so as to concentrate the weight on a small part 

 of the rim. These stones then revolve round a central 

 pivot in a circular trough. The advantage of stones 

 revolving horizontally and vertically at the same time 

 is, that they grind as well as roll or crush the seed. 



The cakes are slightly heavier than linseed cakes, 

 and run about 160 to the ton with Egyptian cakes 

 containing 5 per cent, oil, and 150 in Bombay cakes 

 containing 4^ per cent. oil. 



Soya Beans. The leguminous plant called soya 

 bean (Glycine hispida) is largely grown in Manchuria, 

 Northern China, Japan, America, etc., and produces 

 seeds in pods about the size of an ordinary pea. The 

 colour of these seeds is generally yellow. They con- 

 tain 16 to 20 per cent, of oil, and on this account 

 are not largely fed to stock without having a part of 

 the oil extracted. If the pure seed is fed to stock, it 

 should be mixed with foods which are rich in carbo- 

 hydrates, such as maize or other cereal grains, and 

 only up to the extent of one quarter of the concentrates 

 given. 



These seeds are also rich in albuminoids (36 per 

 cent.). The nutrients are very digestible. 



Hemp Seed (Cannabis sativa). This is a small 

 whitish seed, very rich in oil (33 per cent.), moderately 

 rich in albuminoids (16 per cent), poor in carbohydrates 

 (ij per cent), and very low in fibre (2 per cent). The 

 nutrients are also very digestible. The residue after 

 the oil has been expressed should only be fed to cattle, 

 and even then in small quantities at a time. 



Ground-nut, or Pea-nut (Arachis hypogoeci). The 



