Agricultural Chemistry. — Pirj Feeding, 



523 



ones, to afford the same equivalent of respiratory and fat- 

 forming material — and again, that the nitrogenous consti- 

 tuents, if they took any part in these processes, would have 

 also their own special equivalent or capacity, in these respects. 

 Further, it should be borne in mind, that even after all due 

 allowance has been made for those various sources of discrepancy 

 in the actual figures of the Tables to which we have referred, the 

 amounts which we may suppose to be thus corrected, would still 

 include all those variations — vv^hether arising from differences 

 of external circumstances — from individual peculiarities in the 

 animals themselves — from the different amounts stored up as 

 increase according to the adaptation of the foods — or from the 

 many other uncontrollable circumstances, which must always 

 interfere with any attempt to bring within the range of accurate 

 numerical measurement, the results of those processes, in which 

 the subtle principle of animal life exerts its influence. 



Bearing then those points in mind, which must tend to modify 

 the indications of the actual figures in the Tables, it will appear, 

 Vi^e think, that the coincidences in the amounts of available 

 respiratory and fat-forming constituents, consumed by a given 

 weight of animal within a given time, or to produce a given 

 amount of gross increase, are much more strikingly shown 

 throughout the numerous results represented in these Tables, 

 than a priori we could have expected to find them. With this 

 general uniformity, however, as to the amounts of non-nitrogenous 

 substance, consumed under given circumstances, or to produce a 

 given result, those of the nitrogenous constituents are found to 

 vary in the proportion of from one to two., or even three ; very much 

 more indeed, than is consistent wdtli the idea that the supply of 

 these had regulated either the amounts of food consumed, or of 

 increase produced. There may, indeed, be some individual dis- 

 crepancy in the figures, not easily accounted for by any of the 

 circumstances to which we have referred ; and which might 

 perhaps appear to lead to opposite conclusions to those vv^hich 

 we w^ould draw from the Tables as a whole. But, we think it 

 will be much more reasonable to attempt to explain — or, con- 

 sidering the nature of the subject, even to admit as inexplicable — 

 a few discrepant cases, than to reject, on their account, the 

 general testimony of much more numerous, consistent, and other- 

 wise sufficiently conclusive results. 



Looking first to Table XXIL, which gives the amounts con- 

 sumed loeekly -per 100 lbs. live iceight in Series I., we find, that 

 there is a generally less amount of the 7io?z-nitrogenous consti- 

 tuents consumed in the first set of four pens than in the second. 

 This somewhat less amount of non-nitrogenous constituents con- 

 sumed per 100 lbs. live weight per week in the first set, is, how- 



