390 POOD AND FEEDINO. 



wurzel, according to Thaer, is represented by 1012 ; while Mayei 

 and Pabst call it but 550, ^ud M. de Dombasle states it a little high- 

 er, viz. 574. However highly we estimate the difficulties of com- 

 ing to accurate conclusions on the subject of alimentation or feeding, 

 it is not easy to account for such discrepancies among practical 

 men ; and then, as to the astonishing similarity which their conclu. 

 sions bear to one another upon many heads, it is impossible to over- 

 look the fact, that the resemblance is far more in appearance than 

 in fact ; for it is notorious, that the generality of those who have 

 committed themselves to writing have generally copied each other. 

 Indeed, it is not always very obvious whether the equivalent number 

 which we find assumed, has been determined by the farmer from his 

 own observation or experience, or has been adopted from some other 

 observer. No one who is not a total stranger to the art of making 

 experiments will ever be brought to believe that eleven experiment- 

 ers, operating separately, could have fallen plump upon the number 

 90 as the equivalent for lucern, or even that any five of them could 

 have lighted upon 600, neither more nor less, as the equivalent num- 

 ber for cabbage ! 



The method which I have myself pursued, that namely of infer- 

 ring the nutritious quality from the contents in azote, is far from 

 being free from objection ; on the whole, it may be said to place the 

 equivalents somewhat too low, inasmuch as by the process of ele- 

 mentary analysis, the quantity of azote is apt to come out a little too 

 high, some portion of it being derived from the nitrates present in 

 vegetables, which are certainly of no avail in nutrition. This is the 

 source to which I ascribe the anomaly presented by the leaves of 

 mangel-wurzel. And, then, it is not to be forgotten that in dosing 

 the azote we have regard but to the jlesh contained in the article of 

 food, which although unquestionably the principle that is of highest 

 value, and the one which is apt to be most deficient, is still not all. 

 The neutral non-azotized substances, starch, sugar, gum, oil, are in- 

 dispensable as auxiliaries in the alimentation of cattle ; the three 

 first undergo changes in the course of the digestive process which 

 fit them to be absorbed immediately, and the oil is brought to the 

 state of an emulsion, and so is taken up and adds to the fat. The 

 woody fibre alone of vegetables appears to have no direct share iu 

 the nutrition of animals ; it is discovered almost or altogether un- 

 changed in the dejections. 



It is therefore every thing but matter of indifference whether a par- 

 ticular article of forage contains a larger or a smaller proportion of 

 starch, sugar, &c., associated with a given quantity of azoti/ed or 

 truly animalized matter. The potato and meadow-hay brought to 

 the same state of dryness, contain as nearly as possible the same 

 proportions of azote — from 1.3 to 1.5 per cent.; in other words, about 

 8^ per cent, of albumen and gluten, i. e., of flesh. But in the pota- 

 to, almost the whole of the 9U per cent, of the remainder consists 

 of starch ; while in hay it is woody fibre, inert matter as we must 

 presume it, that is present in by far the largest proportion. And 

 this explains the higher value of the same weight of dry potato a4 



