FOODS. 93 



In the first column tlie whole of the nitrogen in the 

 food is reckoned as existing as albuminoids; in the second 

 column the true albuminoids only are taken account of. 

 In calculating the second column it has been assumed 

 that in a digestion experiment the amides and nitrates, 

 being soluble bodies, would be reckoned as "digestible 

 albumin ; " the amides have not, however, been reckoned 

 among the non-albuminous constituents, their equivalent 

 in starch not being yet known. 



The figures show in a strikino^ manner the wide differ- 

 ences that exist among foods as to the proportion of 

 albuminoids which they supj)ly, the difference being made 

 still more considerable by the recent discovery that a large 

 part of the nitrogen in certain foods exists as amides and 

 not as albuminoids. Mangels now appear as a food very 

 poor in albuminoids, whereas they were formerly supposed 

 to supply a sufficient proportion ; and the same is doubt- 

 less true of other roots not yet thoroughly examined. 



The poverty of a diet of roots and straw chaff" in 

 digestible albuminoids is the true reason of the excellent 

 effects produced by the addition of oilcake or leguminous 

 corn. Oilcake and beans used under these circumstances 

 have an effect far above their own intrinsic feeding value, 

 as their presence raises the character of the whole diet, 

 and enables the carbo-hydrates of the roots and straw to 

 contribute to the formation of carcase. 



It must be recollected that the albuminoid ratio of a 

 food may be diff'erent for different animals if their powers 

 of digestion are unequal. Thus the same meadow hay 

 supplied to sheep and horses had for the former an albu- 

 minoid ratio of 1 : 9*1, and for the latter a ratio of 1 : 6*7. 

 The horse, as we have seen, digests the nitrogenous con- 



