100 PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 



The seller of the first of these cakes assured the buyer that 

 it was " the best in the world," and there is certainly nothing in 

 the analysis of either sample calculated to excite suspicion. In 

 fact the buyer, who decided merely by the analytical numbers, 

 would at ouce accept these as genuine, and yet they were fouud, 

 on careful examination, to contain both bran and rape. The 

 quantity of bran appeared to be about the same in both samples, 

 but the rape was more abundant in the first than in the second. 

 There is no method of determining exactly the proportion of 

 these substances in a cake, but I should estimate it at about 20 

 to 25 per cent, of the two substances together in No. 1, and 

 somewhat less than this in No. 2, but the general resemblance 

 of the two samples is so great that I am inclined to suspect they 

 may be from -the same maker, although they were sent to me 

 from two entirely different parts of the country. If now we 

 look to the value of these cakes it becomes necessary to consider 

 that of the substances of which they are made up. A genuine oil 

 cake may be assumed to cost about £11 per ton, and bran and 

 rape cake about £6 .* And assuming a cake contain 25 per cent, of 

 these substances, its extreme value should be £9 15s. per ton. 

 But it could not be sold to the farmer at that price. And the reason 

 for this is that the manufacturer cannot mix together linseed, 

 rape, and bran, and press the mixture, because, if he did so, he 

 would get a mixture of linseed and rape oils, which would either 

 be altogether unsaleable, or would bring a price materially less 

 than could be obtained if each was sold in the pure state. He 

 must therefore press the two seeds separately, grind them down 

 and mix them with the bran, and press them a second time into 

 cakes ; and as this operation cannot cost less than 15s. per ton, 

 it is obvious that he must sell the cake at £10 10s. if he is to 

 obtain a profit. The farmer must therefore be charged 15s. per 

 ton for allowing himself to be deceived ; and this is the most 

 favourable view of the case, for the chance is that £11 will be 

 asked for the article, and very possibly 5s. or 10s. more, on the 

 plea that it is " the best cake in the world." 



The necessity of re-pressing the cake when an oily seed is 

 to be used for adulteration limits to some extent the use of these 

 substances, and confines it chiefly to those cases in which a large 

 quantity of spurious matter is added to the cake. The most 

 common practice is to add to the linseed a substance containing 

 little or no oil, so as to enable the crusher to sell his cake at a 



* At the present moment the price of rape cake has risen to £7 per ton, in 

 consequence of the short crop of the past season. The usual price is about £5 

 10s., both for it and inferior bran, but I have chosen £§ as a fair value. 



