536 



Agricultural Chemistry. — Pig Feeding, 



feeding-slied, or even on the table ? We have, it is true, much 

 yet to learn, of those minor differences of composition, to which 

 are due the greater or less adaptation to the instinctive wants of 

 the system, of the various constituents of which our staple articles 

 of food are made up. But we think, that in no considerations of 

 this kind, could we seek an adequate solution of our question. 

 On the other hand, we believe, that in the Leguminous seeds the 

 due proportion of the nitrogenous to the non-nitrogenous con- 

 stituents is not observed. If this be true, it is obvious, that in 

 the use of the Leguminous seeds instead of the Cereal grains^ 

 more than is requisite of the nitrogenous constituents will be 

 taken into the system, before the adequate supply be attained, of 

 the ?zo?2-nitrogenous or respiratory and fat-forming materials, 

 Nor, as our markets go, would the relative prices of these seeds 

 and grains be found to interfere with a somewhat lavish use and 

 expenditure of nitrogenous compounds in the former. 



In the facts which are here briefly stated, we have surely 

 very curious and interesting matter for reflection ; and we have 

 brought to our view, a striking instance of the mutual adapta- 

 tions which are everywhere traceable in the practical application 

 of natural laws. Thus, we have said, that under given circum- 

 stances, the Leguminous crop will give a much larger acreage 

 yield of nitrogen than the Cereal grain ; and that an increase of 

 produce of the latter is not obtained by the use of nitrogenous 

 manures, except at the cost of more nitrogen in the manure than 

 is contained in such increased produce ; whilst, in point of fact, 

 in the ordinary practice of rotation in this country, the growth 

 of a Leguminous corn or fodder crop, v/ith its high percentage 

 and actual amount of nitrogen, is itself, frequently either the 

 direct or indirect source of the nitrogenous manure by which 

 the increased Cereal is obtained. And, again, this Cereal, ob- 

 tained at the cost of, but with its lessened produce of- — nitrogen, is 

 found in practice to be, weight for weight, of equal, or of a more 

 highly feeding value, than the more highly nitrogenizecl Legu- 

 minous product, which perhaps has been expended to produce 

 it. It would thus appear, that the demands of the respiratory 

 function, which have been seen more than any other to regulate 

 the consumption of food, would, in point of fact, not be sr?.tisfied 

 in the use of the Leguminous diet, unless by a consumption or 

 expenditure of an amount of nitrogen beyond that which the 

 due balance of the constituents of food would seem to require ; 

 whilst, on the other hand, in the use of the Cereal grain, its 

 better proportion of the 720?2-nitrogenous to the nitrogenous con- 

 stituents, has only been attained, l3y the sacrifice of nitrogen ex- 

 pended in its growth. It would seem, then, that whether we' 

 would seek our supplies of food in the direct use of the highly 



