244 
The Applications of Physiology 
of a plant is wholly engaged in increasing the mass of its sub- 
stance, and that none of it is expended in executing the commands 
of volition. In stall-feeding cattle we impart to them a vegetative 
life. The vitality of the animal in its natural or wild state is 
principally employed in executing vital movements, but in the 
stall these are in a great measure prohibited. Now this mys- 
terious principle of life is never at rest. Its powers are, therefore, 
employed in increasing the mass of the body in which it resides. 
Whilst pigs are growing, they are permitted the use of a yard ; 
but when it is desired to fatten them, they are confined to a sty. 
This confinement is to prevent any waste of matter in the pro- 
duction of motion. Some even confine the pigs in sties so narrow 
that they are unable to turn, and as dark as possible, in order to 
induce them to sleep. Most farmers are aware of the fact that 
young calves, sheep, and pigs fatten more quickly in the dark 
than in the light. The explanation of this fact is simply this, 
that they pass more of their time in sleep. Sleep is that portion 
of the life of an animal when the principal growth of its body 
takes place. In sleep all the voluntary motions cease : vitality, 
therefore, now increases the mass of the body, as its force is not 
expended in producing motion. It is for this reason that we like 
those lethargic pigs which stagger to the trough in a lazy way, and 
sleep as soon as they have finished eating. Very little matter 
being expended in motion, they rapidly increase in size. The 
phlegmatic Chinese or Neapolitan pig fattens quickly, whilst the 
unimproved, long-legged Irish pig, which gallops about at such 
an extraordinary rate, expends all its food in the production of 
force,* and does not grow rapidly. 
Perhaps the greatest refinement in fattening is exhibited in the 
manner of feeding ortolans. The ortolan is a small bird esteemed 
a great delicacy by Italians. It is the fat of this bird which is so 
delicious; but it has a peculiar habit of feeding, which is opposed 
to its rapid fattening — this is, that it feeds only at the rising of 
the sun. Yet this peculiarity has not proved an insurmountable 
obstacle to the Italian gourmands. The ortolans are placed in 
a warm chamber, perfectly dark, with only one aperture in the 
wall. Their food is scattered over the floor of the chamber. At 
a certain hour in the morning the keeper of the birds places a 
lantern in the orifice of the wall; the dim light thrown by the 
* Dr. Dnny, the physician to the private lunatic asykim in Glasgow, in- 
formed me that very violent patients eat an enormous quantity of food, and 
yet never become fat ; while low lethargic patients (when they are not 
melancholic) have great tendency to become so. In the first case, the 
violent muscular exertions of the unhappy patients exhaust the food which 
they consume ; in the latter case, it produces increase of size, from not 
being expended in the production of force. 
