
FOODS, IN RELATION TO RESPIRATION AND FEEDING. 339 
will be much more reasonable to attempt to explain, or even considering the 
nature of the subject, to admit as inexplicable, a few discrepant cases, than to 
reject on their account the general testimony of much more numerous, more 
consistent, and otherwise sufficiently conclusive results. Thus in the first 
set of four pens in this series, there is, upon the whole, a less amount of the 
non-nitrogenous constituents consumed than in the second; and this lessened 
amount of non-nitrogenous constituents consumed in the former is seen to be 
coincident with excessive consumption of the nitrogenous ones, and it is even 
the less the greater that excess. It isalso worthy of remark, too, that in pens 
5 to 8, where there was this larger amount of non-nitrogenous substance 
consumed, it was supplied chiefly by Indian corn meal, which, containing 
more oily matter than that of the foods in pens 1 to 4, would also possess a 
higher respiratory and fat-forming capacity, weight for weight, than that in 
the other cases. We may here suppose, that perhaps a surfeit of the nitro- 
genous substances put a limit to the further consumption of non-nitrogenous 
constituents which would otherwise have been taken; or, that being in excess, 
the nitrogenous substances have substituted other respiratory material ; and 
it is consistent with such a supposition, that with the less amount of non- 
nitrogenous constituents consumed, where the nitrogenous are in excess, there 
is nevertheless a larger amount consumed of fofal organic substance than 
where there is more of the non-nitrogenous constituents. 
That a larger amount of the complementary food was consumed when it 
consisted of the comparatively low nitrogenized Indian meal, was not due 
only to a craving for a supply of nitrogen which a less quantity would not 
have yielded, would appear, among other consideraticns, from the fact, that 
when, after a time, the pigs in pen 5, where Indian meal alone was given, 
had become affected with large tumours breaking out on their necks, 
their breathing and swallowing becoming at the same time difficult, we, in 
order to test the question as to whether this arose from a defect of nitrogen 
or from other causes, supplied them with a trough of mineral substances: they 
soon recovered from their complaint, and eventually proved to be among the 
fattest and best of the entire series of pigs; at least, a dealer in pork with 
a practised eye, purchased by preference one of these animals from among 
the whole set of carcases. The mineral mixture that was supplied to them 
was composed of twenty parts coal ashes, four parts common salt, and one 
part superphosphate of lime; and for it they seemed to exhibit considerable 
relish. 
In pens 9, 10 and 11, a comparatively small quantity of the more digestible 
foods was allowed, the complementary food being in these cases bran; and 
as we have before said, the digestive apparatus of the pig is not adapted for 
a large amount of bulky woody substance. Here the animals consumed a 
less amount of non-nitrogenous substance in proportion as the bran predo- 
minated in their food ; and they at the same time also increased and fattened 
much less than those in the other pens. In fact, until 3lbs. per head per day 
of the limited foods were allowed instead of only two, as was at first given, 
several of the pigs lost weight and became unwell; being as it were paralysed 
(gouty ?), and almost deprived of the use of their legs. There can be little 
doubt that the proportion of woody matter in the bran, which food only 
they had at full command, was too great for the convenience of their sto- 
machs ; and that hence, after their respiratory requirements had been fulfilled; 
a limit was put to further consumption to serve the mere purpose of fattening. 
In pen 12, the several foods, namely, the bean and lentil mixture, the 
Indian meal, and the bran, were each put into a separate trough, and the 
animals were allowed to take of all or any of them ad libitum. Were it not 
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