PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 191 



price slightly below that at which the genuine article is offered, 

 and for this purpose bran is the material most commonly em- 

 ployed, but oat dust, rice dust, the husk of buckwheat, and 

 similar refuse vegetable matters are used, and many sub- 

 stances which were formerly thrown away have now a definite 

 commercial value, and are regularly offered to the oil crushers. 

 Kice dust, for example, which is produced in considerable 

 quantity in the manufacture of rice flour, is all absorbed by the 

 crushers at a price of £3, and so it is with many other sub- 

 stances. When these adulterating materials are used in small 

 quantity, to the extent, for instance, of 10 or 15 per cent, the 

 most practised eye cannot distinguish any difference in the ap- 

 pearance of the cake. Indeed, it not unfrequently happens that 

 it looks better than the genuine article, but when the amount is 

 large, it can scarcely fail to attract attention. The cake has theu 

 a paler colour, is much softer, and splits into scales with greater 

 or less ease. These characters are most distinctly seen when 

 coarse bran has been used. If it has been finely ground they 

 are less apparent, and with rice dust the tendency to split is 

 scarcely apparent, but this, no doubt, is partly due to the fact 

 that that substance cannot be used in very large quantity, as it 

 renders the cake too pale in colour. 



As examples of cake adulterated with very large quantities 

 of substances which do not themselves yield oil, I give the fol- 

 lowing analyses : — 



The first of these cakes, though rather pale in colour, was in 

 other respects satisfactory to the eye, and might have perfectly 

 well passed for a genuine sample. Analysis, however, at once 

 disclosed the fact that it could not be genuine, and a further 

 examination proved that it contained abundance of bran, and I 

 estimate the proportion at not less than 40 or 50 per cent. In 

 fact a mixture of equal weights of good linseed and bran would 

 contain about 20 per cent, of albuminous compounds, while the 

 sample contained only 14-68, and from this fact I am inclined 



