142 PLANT PRODUCTS 



cake lias a very dry and unsatisfactory flavour. Unless 

 it be mixed with some damp food the cattle will merely 

 blow it away with their noses, and never eat it at all, but if 

 it be moistened, or mixed with turnips, the cattle, after a 

 little experience, can be induced to eat it. The difficulty 

 under this head is only what has been observed on many 

 occasions before, cattle do not take readily to new-fashioned 

 food, and it takes a good deal of patience and persuasion 

 to induce them to eat something they have never tasted 

 before. In time, of course, these difficulties are overcome. 



Earth Nuts. — The earth nut, or ground nut, is a tropical 

 annual leguminous crop which has the peculiarity that the 

 fruits bury themselves in the earth. It will grow in sandy 

 soils, is very valuable as a course in tropical rotations, and 

 lends itself well in conjunction with cotton on irrigated light 

 land. In some cases the ripe fruits are actually dug out of 

 the earth, or in others the crop is taken before the fruits 

 have had time to enter. Earth nuts are largely grown in 

 Madras, and shipped from Pondicherry to Marseilles. The 

 best qualities come from Rufisque, in Senegal. Sometimes 

 the pods are removed from the beans, and sometimes the 

 materials are pressed whole. The actual bean contains 

 about 40 to 45 per cent, of oil, and 28 per cent, of albuminoids. 

 Earth nuts are not infrequently fractionally expressed, the 

 best quality oil, cold drawn, being expressed at the ordinary 

 temperature, and one or two other fractions made at 

 increasing temperatures afterwards. The best qualities 

 of oil, that is, those that are cold drawn, are used in the 

 manufacture of salad oil, and the second qualities for the 

 preservation of sardines, and the manufacture of margarine. 

 The lowest quality, that expressed at the highest temperature, 

 is used for soap-making. A characteristic fatty acid of 

 earth nuts is arachidic acid. Earth-nut oil is a non-drying 

 oil. Earth-nut oil is largely used to replace olive oil in all 

 its uses. When the husks are removed, the resulting cake 

 contains 7 to 9 per cent, of oil, and 45 to 48 per cent, of albu- 

 minoids, and 5 to 7 per cent, of fibre. When the husks 

 have not been removed, the fibre may vary from about 



