Oil-cakes. 13 



weight, linseed-cake is much better than rape-cake. It is not, I 

 believe, difficult to account for this superiority. 



In the first place, I would observe that rape-cake has a strong 1 , 

 hot taste, and is not liked much by cattle ; whereas good linseed- 

 cake is sweet and agreeable to the taste. The natural appetite of 

 animals, to a certain extent, it strikes me, may be regarded by us 

 as a guide to what is good or bad for them ; and though a 

 dislike for a certain food may be overcome in time, I believe an 

 animal will never get on so well upon food which it naturally 

 dislikes as upon another for which it is greedy. 



2. In the second place, it may be stated that the oil of rape- 

 seed naturally possesses a disagreeable smell and taste, and is apt 

 to turn rancid. Rape-cake, which contains about 11 per cent, of 

 this oil, thus has a great tendency to become rancid, and conse- 

 quently unpalatable to cattle. 



3. In the third place, I would observe that rape-cake contains 

 a much larger proportion of indigestible woody fibre than linseed- 

 cake ; whereas the latter contains on an average about 9 per cent, 

 of woody matter, the former contains as much as 20 per cent., 

 and even more. 



As stated above, the proportion of substances not containing 

 nitrogen is almost as great in rape as in linseed-cake. But as in 

 the case of rape-cake, about one half of these substances consists 

 of woody fibre, Avhich is of no use whatever to the animal, and 

 as linseed-cake contains only 9 per cent, of indigestible fibre, it 

 is clear that linseed-cake must be superior in this respect to rape- 

 cake. 



4. Lastly, it may be as well to bear in mind that good linseed- 

 cake is hardly if ever adulterated, and seldom mixed with foreign 

 seeds, whereas rape-cake contains more frequently than any other 

 description of cake the seeds of weeds. The experienced eye 

 will find no difficulty in recognizing in rape-cake the seeds of 

 mustard, charlock, and other weeds. Some of these seeds possess 

 a disagreeable, bitter, or acrid taste, and possibly may possess 

 poisonous properties. 



I would direct special attention to the fact that rape-cake often 

 contains a considerable proportion of mustard-seed. In Belgium, 

 France, and Germany, where much rape is grown on account of 

 the oil which its seed furnishes, the fields are often very foul 

 with mustard ; but as mustard itself is grown on account of its 

 oleaginous seed, no care is taken to eradicate it, and hence it is 

 that rape-cake contains frequently much of the expressed seeds of 

 mustard. This admixture is injurious if the cake is given to 

 fattening cattle in any quantity. Sheep do not appear to be 

 affected so much as cattle by mustard. Rape-cake, which is 



