
FOODS, IN RELATION TO RESPIRATION AND FEEDING. 343 
substance in the exclusive turnip diet would be less than in the other instances ; 
and hence the larger amount consumed for a given result. 
Turning to the results of the second series, with clover-chaff instead of 
turnips as the ad libitum food, we have, with the larger amount of woody 
fibre, which would become at once effete, much more gross non-nitrogenous 
matter consumed to produce 100 Ibs. of increase than in Series 1. This is 
less, however, in pens 1 and 2, with the large proportion of oleaginous matter, 
-than in pens 3 and 4. There is, moreover, in this second series, with this 
greater amount of zon-nitrogenous matter consumed for a given effect than 
in Series 1, a much larger amount also of the nitrogenous constituents ; the 
gross amount of the latter, indeed, in this second series, is twice, and even 
sometimes thrice as great as in Series 1. 
In the next series, namely, Series 3, with barley and malt in different states 
and proportions as limited food, and mangold-wurtzel as the complementary 
food, we have, upon the whole, about the same amounts of non-nitrogenous 
substance required to produce the same result as in Series 1, with, besides, a 
small quantity of grain or other limited food and Swedish turnips as the com- 
. plementary food, which latter are in great degree comparable with the mangold- 
wurtzel; and of course, as in Series 1, the average amount is very different 
from that in the second series with the large proportion of clover-chaff. 
Looking to the three total columns, namely, of nitrogenous, of non-nitrogen- 
ous, and of total organic constituents consumed, although it is true the dif- 
ferences are not great, and perhaps such as might be covered by differences 
in the composition of the increase, yet it may be noticed, that larger amounts, 
both of non-nitrogenous and of total organic substance, were consumed to_ 
produce the same result the larger the proportion in the latter of the nitro- 
genous constituents. 
In Series 4, we have a more marked instance of the result last noticed. 
But, apart from the question as to whether the increase of the fattening 
animal has a closer relationship with the amount of the true proteine com- 
pounds, or, within certain limits, of the available non-nitrogenous constitu- 
ents of its food, we have here a striking illustration of the inapplicability on 
other grounds of the per-centage of nitrogen as the measure of feeding value, 
or indeed of any analytical method, unless a detailed determination of the 
proximate compounds, when succulent products, such as in this instance, the 
roots, are the subjects of the experiment. Thus, in the fourth pen of this series, 
where there was by far the largest amount of nitrogen consumed, the animals 
lost weight; and in the other three pens, the productiveness of the food is in 
the inverse order of the amounts of nitrogen taken in the food. This arose of 
course from the different states of maturity, and the consequent state of elabo- 
ration of the constituents of the various turnips, the produce of the different 
manures. Indeed, we believe that an unusually high per-centage of nitrogen 
in succulent produce is frequently a pretty sure indication of immaturity and 
innutritious qualities. Comparing the results of this series with those of the 
others, we have, considering how small would be the proportion of inert 
woody fibre in the unripe turnips, about twice as much dry substance (in 
pens | and 3 at least) consumed to produce a given amount of increase—a 
difference which could, at any rate in only a small degree, be accounted for 
by any difference in the capacities of the digestible and available portions of 
the foods in the cases thus compared. 
Considering only the ostensible similarity of the foods in the several pens 
constituting the 5th and last series of experiments with sheep, there is, per- 
haps, no more of coincidence in the amounts that have been required to pro- 
duce a given increase in the different pens, than, judging from previous 
results, we might have anticipated. From what we know, however, of the 
