Beans and Peas, 8fc. 



487 



obtain the greatest advantage from a given weight of food, either 

 in feeding or fattening, it is necessary that the flesh-forming, fat- 

 producing, and heat-evolving principles should bear a certain pro- 

 portion to each other.* Of what that proportion may be, we are 

 at present ignorant. Practical men are nearly agreed that, in 

 linseed itself, the quantity of oil is, in relation to the nitrogen, 

 too great for the general purposes of cattle-food, and that the two 

 ingredients are better proportioned in cake ; but it does not follow 

 that 13 per cent, may not be a more advantageous proportion 

 than 9; and although an opinion on this subject would be pre- 

 mature, I would suggest to the intelligent farmer to bear this 

 peculiarity in mind in any trials which he may institute between 

 the cakes of different countries. 



Having by the preceding analyses given answers to the first 

 and second points of inquiry which were proposed in the com- 

 mencement, namely, first, whether there existed any real differ- 

 ence in chemical composition, and if so, whether there was any 

 marked distinction between the cakes of different countries, and 

 secondly, whether the variation was sufficient to account for ob- 

 served effects in feeding, we may pass on to inquire, thirdly, Is 

 the difference attributable to adulteration, or to necessary variation 

 in the composition of the seed? 



Adulteration might be effected in two ways, either by admix- 

 ture with the cake of sand or other earthy matter, or of sawdust, 

 bran, or other vegetable substance. 



I omit in this place the deterioration produced by the use of 

 mixed and badly harvested seed ; for although no doubt this is 

 of very common occurrence, and very prejudicial to the interests 

 of the consumers of cake, it is hardly to be called adulteration — 

 a term which we apply to the wilful and dishonest falsification of 

 any article of commerce : but of this there will be presently 

 occasion to speak. 



In the first place, then, Is cake ever adulterated with sand or 

 earthy matter ? Farmers are in the habit of taking a portion 

 between their teeth, and, should they find it " gritty," believe 

 that it is so adulterated. To me it has always seemed unlikely 

 that the cake-manufacturers should resort to so clumsy a method 

 of falsification, because, if the mixture of sand should be made 

 with the meal during the earlier pressings, it would not only 

 diminish greatly the yield of oil", but would increase to an im- 

 portant extent the labour of its extraction. If, on the other hand, 

 the mixture were reserved till after the complete extraction of the 

 oil, it would demand an additional pressing. Unless, therefore, 



See Mr. Lawes's paper on Sheep-Feeding in the last (July) Number of this Journal. 



2 k 2 



