March 1907.] 



159 



Edible Products*. 



The imports of decorticated nuts in 1897 were only 1,000 lbs. of ground-nuts 

 in the shell, 138,102 lbs. 



The exclusion of foreign nuts is well shown by the above figures, which may 

 be taken in conjunction with the statements that in years of low prices the cost of 

 transport precluded the importation of African huts (Journ. Applied Science. 1881, 

 p. 81), and that in 1894, owing to the tax, nuts sent from Africa met with no market 

 (U. S. Consular Reports, Oct., 1894. p. 240). 



Expression of the Oil in Europe. 

 The oil is expressed from the seeds in the following manner, as described 

 by Dr. P. Uhlitzch (Die Landwirtschaftlichen Versuchs-stationen, Xli., 1892, p. 

 400) :— " When by means of brushing the pods the unshelled nuts have been cleaned, 

 they are broken between rollers and passed on to a fan which winnows out the light 

 pieces of husk. When the seeds are sufficiently broken they are packed into a 

 cylinder in thin layers, each layer separated by a cloth of horsehair. The first 

 pressing is but slight the resulting cakes are very flat, loose, and easily broken. The 

 cakes are then broken and ground up finely in a mortar, sprinkled with water and 

 mixed with any meal which passed through the holes in the cylinder at the first 

 pressing. Then follows the second pressing. Mills which make only table oil express 

 twice in the cold, or on the second occasion in very slight heat ; but usually the nuts 

 are pressed three times. 



" The first expression in the cold gives an almost colourless oil with agreeable 

 taste and smell, which serves as pure table oil, and is used for making oleo-margarine ; 

 the second yields a " sweet oil," and the product is also used for burning ; the third 

 expression, made with heat, gives an oil— rabat oil— of a yellow colour and hardly 

 agreeable taste and smell, which is used in soap-boiling. "By these different press- 

 ings 30-40 per cent, of the oil is removed in something like the following proportions :— 

 ,, 1st expression, 10-18 per cent, of a fine table oil 

 ,, 2nd ,, 7-8 ,, of a table oil or illuminating oil. 



,, 3rd ,, 7-8 ,, of an indifferent oil. 



" The oil cake left contains about 7'5 percent." Such is the result of expression 

 carried on at the mills of Hamburg, Berlin, Marseilles, Rouen, &c. According to 

 Houze, the nuts in Spain, when pressed as soon as gathered, often give 60 per cent. ; 

 in Italy 50 per cent, is obtained, in India, 43 per cent., in Senegal, 30-33 per cent., and 

 at Pondicherry, 37 per cent. 



The bags used in the process are made of horse hair or wool. The cake varies 

 in shape according to the machinery used. Those made in Riga are twice as long as 

 those made in West and South Germany. When it is intended to devote the whole 

 of the oil to soap boiling chemical means are used in its extraction — carbon bisulphide, 

 petroleum-ether, benzene or canadol. The use of such substances as carbon bisulp- 

 hide obviously leaves the cake unfit for food. 



The Indian Oil Mill. 

 The Indian oil mill/was described by Subba Rao in the Bulletin of the Depart- 

 ment of Land Records and Agriculture, Madras, (p. 283 no. 28, 1893) in the following 

 way :— 



"The oil is expressed locally in native mills of the ordinary rotary pestle-and- 

 mortar pattern. The chief centres of this trade are Valavanur (700 mills), Panruti 

 (200 mills), and Pondicherry (200 mills). A single charge for a mill is from 15 to 18 

 Madras measures of seed (about 15-18 lbs.), which must be first thoroughly dried. 

 During the pressing water is added to the seed in small quantities. After working 

 for about half-an-houu, oil begins to collect and the kernels to cake. The cake is 

 then loosened with a crow bar, and about } lb. of old ground-nut cake dust is mixed 

 with the mass, and work is then resumed. In 45 minutes from the commencement of 



