Agricultural Chemistry — Sheep- Feeding and Manure. 291 



the other cases, it would appear that the amounts of really digest- 

 ible dry organic food were almost identical in the four cases. The 

 amount of nitrogen, on the other hand, which is consumed by a 

 given weight of animal within a given time, varies exceedingly in 

 the four pens: there being to 100 lbs. live weight per week, 

 0-39 lb. in penl, 0-25 lb. in pen 2, 0 261b. in pen 3, and 0' 17 lb. 

 only in pen 4. If we now turn to Table 8, however, we shall see 

 that the amount of nitrogen required to produce a given increase 

 of weight was almost identical in pens 2, 3, and 4, with oats and 

 swedes, clover and swedes, and swedes only, respectively : whereas 

 in pen 1, with oil-cake, in which by far the largest amount of 

 nitrogen was consumed within a given time, a less effect w as pro- 

 duced by a given amount of it. It would thus appear that con- 

 sumption is regulated much more by the amount of available non- 

 nitrogenous substance in the food than by that of nitrogen ; whilst 

 the increase would seem to bear a much more direct relation to the 

 quantity of nitrogen consumed, when this does not exceed a certain 

 limit — beyond which, however, the proportional effect would ap- 

 pear to be lessened. From Table 8, again, we gather that although, 

 in pen 4 with swedes alone, a given amount of nitrogen produced 

 an effect equal to that of any of the other foods, yet this would 

 seem to have been attained at the cost of a larger consumption of 

 available 720?z-nitrogenous food ; for not only is the gross amount 

 of dry-organic-matter consumed to produce 100 lbs. increase 

 greater in pen 4 than in any of the others, but it is supposed that 

 less of it would be necessarily at once effete than in any of the 

 other cases. From these facts we learn, that, so far at least as the 

 production of increase is concerned, the nitrogenous constituents 

 were, in pen 1 with oil-cake, in excess over the available non- 

 nitrogenous ones; whilst in pen 4, on the other hand, where 

 sw r edes alone were given, they were in defect. 



Turning to the general rather than to the particular facts 

 brought to view, we find — taking the average results of 15 sheep 

 fed for 14 weeks on oil-cake, or oats, or clover-chaff, and swedes, 

 as shown in the bottom line of Table 7 — that every 100 lbs. live 

 weight of animal consumed weekly 6j lbs. of the special foods, 

 and 76| of swedes, which contained together 13^-lbs. of dry- 

 organic-matter, f lb. of mineral matter, and 0*3 lb. (about 5 oz.) 

 of nitrogen ; and from Table 8 we learn that 377 lbs. of the spe- 

 cial foods and 4658 lbs. of swedes— the two containing 814 lbs. of 

 dry-organic-matter, 46f lbs. of mineral matter, and 19| lbs. of 

 nitrogen — were required to produce 100 lbs. increase in live 

 weight. The results of pen 4 are excluded from this estimate, 

 as the food consumed in it, being almost wholly swedes, can 

 scarcely be compared with those of the other pens, nor was it, 

 like them, such as is usually considered sufficient for animals 

 preparing for the butcher. 



