534 Agricultural Chemistry. — Pig Feeding. 



of gross increase produced — yet still, so far as thej go, they are 

 consistent in their indications. 



Reviewing, as a whole, the results of the Three Series of experi- 

 ments with Pigs — if we consider, that it is the results obtained 

 tinder the subtle agency of animal life, that we are seeking to mea- 

 sure and express in figures — and if we also bearin mind, the various 

 sources of modification to which our actual figures must be sub- 

 mitted, in order to attain their true indications, we think it cannot 

 be doubted, that beyond a limit, below which few of our current 

 fattening Pig foods are found to go, it is rather their supplies of 

 available ?20?i-nitrogenous constituents, than those of their nitroge- 

 nous ones, that measure, both the amount consumed to a given weight 

 of animal within a given time^ and the increase in weight obtained. 

 This result with Pigs, is too, perfectly consistent with that ob- 

 tained in our experiments with Sheep. 



It will be noticed, that wherever the amount of nitrogenous 

 constituents consumed, either by a given weight of the animal 

 within a given time, or to produce a given amount of gross in- 

 crease, was in these pig-feeding experiments, comparatively 

 large, it was where a large proportion of the Leguminous seeds 

 was employed. Some writers who have taken the per centage of 

 the nitrogenous compounds of food, as the measure of its feeding 

 value, have recognised, and endeavoured to explain in various 

 ways, the fact, that the records of feeding experiments, do not 

 award to the Leguminous seeds, a feeding value in proportion to 

 their richness in these compounds ; and they have supposed, that 

 it is the accepted deductions from the practical feeding experi- 

 ments, and not the theoretical conclusions, that are in error.* 

 Thus it has been objected against the teachings of such experi- 

 ments — that the variations in the composition of foods of osten- 

 sibly the same description used in different cases, has not been 

 determined ; that the test has been the gross increase or loss in 

 weight ; that the increase may be oxAy fat formed from starch, &c. ; 

 that loss in weight, if any, may be the result of activity, and not 

 of defective diet ; that the food in the different cases compared, 

 has been employed in different states, that is, coarse or fine, raw 

 or cooked ; that the animals have been variously circumstanced 

 as to temperature, exposure, and activity ; that individual animals 

 have very various tendencies to increase, and so on. Now, we 

 believe, that not one of all these objections can vitiate the com- 

 parisons which we have made ; unless indeed, in some degree, the 

 one which refers to the difficulty of determining whether the 

 gross increase obtained be composed chiefly of fat formed from 

 the starch and oily series of compounds, or whether of flesh 



* See Postscript at the end of the Paper. 



