TRANSLATIONS FROM CONTINENTAL JOURNALS. 689 
loss of carbon by respiration is variable, and in proportion to 
the more or less rapid exercise and its duration, and without 
exaggeration it might be taken at one third more; as, for 
instance, a horse that emits 2400 gr. in 24 hours in the 
stable, would lose at work 100 gr. more per hour, and taking 
10 hours’ work would be 1 kilogr. These 3400 gr. cor¬ 
respond to the quantity contained in the food, the ration 
being composed of 7 kilogr. of oats and 7—500 of hay. We 
know that these carbonaceous substances contain 176 
per cent, of carbon, and the neutral bodies, as starch and 
sugar, contain 44 per cent. 
Post-horses which work only a few hours a day consume 
more carbon than horses at slow work, working 10 hours a 
day. The latter do well on rations that contain less carbon 
than the former. On the other hand, horses that have to 
undergo violent exercise, lose flesh very fast, although the 
exercise be but of short duration. Such is the case with race¬ 
horses when training. The question may be asked, whether 
all the functions are not equally increased by exercise, and 
the loss of nitrogen and the phosphorus be not increased 
also. The answer to this is, they are not all equally increased 
b y exercise; on the contrary, some are decreased; as, for 
instance, the secretion of milk, the urine, and the semen. A 
horse that perspires much stales less, and consequently 
loses less nitrogen and phosphorus by the kidneys. It is 
true, that during rapid progression, and necessarily acce¬ 
lerated respiration, accompanied by abundant perspiration, 
the action of the kidneys is lessened, for the skin then emits 
a certain amount of nitrogen and other mineral substances; 
but this does not establish the balance, for at the same time 
the skin also gives off a quantity of gaseous matter, amongst 
which carbonic acid forms a large item; but this acid is partly 
derived from the action of the oxygen of the air on the 
carbon of the blood. The inference from these considerations 
is, that animals lose more carbon and less nitrogen when at 
work than when at rest, and hence a large quantity of 
carbonaceous substances are necessary in their food to 
supply the loss. 
In the experiments made on cavalry horses, it was 
found that the substitution of barley for oats was less detri¬ 
mental to the light cavalry horses than to the large horses of the 
heavy cavalry. In the East, barley suffices to keep horses in 
good condition, while oats cause in hot countries, at times, 
serious inconvenience to them, generally rendering them too 
vigorous, even when given only in quantities which would 
be insufficient to sustain horses in cold countries. In 
69 
XXXIII. 
