THE STOMACH. 
273 
This organ is of vast importance in the animal economy j 
in short, it is indispensable to their being; no animal is 
without one. This is not the case with the brain, and much 
less with the heart, as we know that animal life is sustained 
in some species without either. That great anatomist, John 
Hunter, in his physiological disquisitions, showed that the 
existence of a stomach was the chief characteristic between 
animals and vegetables. The stomach has been truly said 
to be the organ of digestion, because within it the aliment 
transmitted to the oesophagus in a crude state undergoes its 
primary and principal change in a process, the object of 
which is to convert it into material for the support of the 
body, and the distribution and transmission of those fluids 
which sustain life and motion in its different parts. 
It must be obvious from the situation of the stomach, 
that it is not only attended with great inconvenience and 
pain, but also danger, to work a horse hard after a full 
meal. Indeed many have sustained irreparable injury from 
this cause. By the action of the diaphragm, the stomach 
must be displaced and forced back in the belly by every 
contraction of the diaphragm or act of inspiration; then in 
proportion to the fulness of the stomach will be the weight 
to be overcome in breathing, and hence the increased ^bour 
of the diaphragm, and consequently the exhaustion of th • 
animal. Besides, if the stomach is very full, and conse¬ 
quently distended, its weight may prevent it from being 
forced sufficiently far back to allow ample room for the 
necessary volume of air which the animal requires during a 
state of exertion. Hence the short, frequent, and oppressed 
breathing during rapid action, and which too often destroys 
the animal. On a journey, a horse should therefore be fed 
moderately and more frequently than in a state of rest 
and care should be taken not to allow him too much 
