314 



THE EOTHAMSTED EXPERIMENTS. 



Armsby's 

 change of 

 opinion. 



Points 

 proved in 

 Rotham- 

 sted experi 

 ments. 



Conclu- 

 sions. 



It must be admitted that the importance of the carbo- 

 hydrates as a direct source of much, if not of the whole, 

 of the fat stored up in the animals which the farmer feeds 

 has been clearly re-established. We have reason to believe 

 that Dr Armsby himself adopts the change of view ; though 

 it will probably be some time before the truth is thoroughly 

 recognised by the younger agricultural chemists. 



It was maintained by Voit and others, that to establish the 

 formation of fat from the carbohydrates, it must be experi- 

 mentally shown that the fat deposited was in excess of that 

 supplied by the food, plus that which could be derived from 

 transformed albumin. But it is obvious that the mere fact 

 that the food contained enough nitrogenous substance for the 

 formation of all the fat that had been produced, would of 

 itself be no proof that that substance had been its source. 

 It has been seen, however, that Voit's requirement was 

 amply fulfilled in the Eothamsted experiments, both with 

 pigs and with sheep ; and hence it must be admitted to be 

 proved, that at any rate some of the stored-up fat must 

 have had another source, which could only be the carbo- 

 hydrates. 



In winding up the discussion, perhaps we cannot do better 

 than reiterate the conclusions given in our paper on the sub- 

 ject in 1866, namely : — 



1. That certainly a large proportion of the fat of the her- 

 bivora fattened for human food must be derived from other 

 substances than fatty matter in the food. 



2. That when fattening animals are fed upon their most 

 appropriate food, much of their stored-up fat must be pro- 

 duced from the carbohydrates it supplies. 



3. That nitrogenous substance may also serve as a source 

 of fat, more especially when it is in excess, and the supply of 

 available non-nitrogenous constituents is relatively defective. 



Food and Milk Production. 



Milk production, and the dairy industry, are of such great 

 and growing importance, and their various branches involve 

 so many points of interest, that much time and space would 

 be required to adequately discuss them. But when consider- 

 ing what are the animal products of value derived from the 

 consumption of food on the farm, it would obviously be in- 

 appropriate not to refer, however briefly, to the question of 

 milk production in some of its aspects. 



Attention must, however, be confined almost exclusively to 

 the great difference in the demands made on the food — on the 

 one hand for the production of meat, that is of animal in- 



