532 



Agricultiuxil Chemistry. — Pig Feeding. 



more beyond a certain narrow limit, this organic substance 

 abounds in nitrogenous compounds, is again seen, on comparing 

 the pens 9 and 10 of this Second Series, with pens 11 and 12. 

 In pens 11 and 12, we have a larger proportion of Barley-meal, 

 and less of Beans and Lentils, and therefore, less of nitrogenous 

 substance consumed, than in pens 9 and 10 ; and with this larger 

 proportion of nitrogenous substance in the food of pens 9 and 

 10, we have from 50 lbs. to 70 lbs. more of gross dry organic 

 substance required to produce 100 lbs. of increase, than in the 

 former. In pens 9 and 10, the food was the same in both cases. 

 But the amounts of total organic substance consumed to produce 

 100 lbs. of increase, vary in the two from 452 lbs. to 479 lbs. 

 In pens 11 and 12, again, the foods were also duplicates. They 

 contained, as we have said, less nitrogenous substance than 

 those of pens 9 and 10 ; and we have in them, the lowest 

 amounts of total organic substance, consumed to produce a given 

 amount of increase, of any in the Series ; nor is there in these 

 two cases, a variation of half a pound in the amount of total 

 organic substance consumed to produce 100 lbs. of increase ; it 

 being in pen 11, 408*1 lbs., and in pen 12, 407*7 lbs. 



Notwithstanding, however, the very clear indications which 

 this Second Series affords, of the much closer connection between 

 the amount of increase produced, and that of the non-nitrogenous 

 or total organic substance of the food, than that of the nitro- 

 genous constituents, it must not be overlooked, that it was in 

 pen 1, where the proportion of nitrogenous substance in the food, 

 was higher than in any other pen, that we have even a slightly 

 less amount of yzo/z-nitrogenous substance, consumed to produce a 

 given amount of increase, than in any other case in the Series. 

 The amount of total organic substance, consumed for the same 

 result in this pen 1, was, however, somewhat greater than the 

 average of the twelve pens, and greater also than in six of the 

 individual pens, in several of which the amount of nitrogenous 

 substance was only about half as great as in this pen 1. It would 

 seem, therefore, that this large proportion of nitrogenous sub- 

 stance in the food of pen 1 , had yielded a comparatively low rate 

 of gross increase ; whilst this increase, the result of the highly- 

 nitrogenous diet, would probably consist in a less proportion of 

 solid fat, and, therefore, in a less proportion also, of real dry 

 substance. 



The results of Series tl., then, very clearly show, the very close ; 

 connection, between the amount of increase produced and the j, 

 supply in the food of the non-nitrogenous constituents, or of j 

 total organic substance — independently of its nitrogen, when this 

 exceeds a somewhat narrow limit ; and again, as in Series I., that 

 the amount of nitrogenous substance, on the other hand, consumed |j 



