242 
ANIMAL. PATHOLOGY. 
She has covered them, more or less thickly, according to their 
wants, with hair, or wool, or feathers, bad conductors of heat, of 
electricity, and of moisture, and resisting for a certain, and often 
a considerable time, their painful or injurious effects. She has 
done more ; she has placed a centinel that never fails to tell of 
the distant approach of the most dangerous of these foes. The 
hair, the wool, and the feathers, are formed of highly elastic 
substances, and all terminate in points. The slightest impression 
made on the extremities of them is rapidly conveyed to the root ; 
and that root is imbedded in a tissue of nervous matter; so that 
from the slightest change of external influence a feeling is commu- 
nicated, allied to, yet different from, common sensation, and which 
can never be overlooked or mistaken. We go into a room in 
which an electrical machine is worked. There is no indication 
from the skin, or from the more delicate sense of touch, to indi- 
cate the change which is taking place in the electricity of the 
atmosphere of that room, and we should approach near enough 
to receive the spark or the shock, without being aware of our 
danger, were it not for the hair, which begins to move and to 
stand on end, and to tell us what is going forward. 
Indications of atmospheric changes by Animals . — The com- 
mencement of the electric change long precedes its palpable and 
manife*t effects ; and thus the animal is placed upon his guard, 
and seeks for shelter, or lays in a provision of food to last him 
during his retreat, before the rain and the storm come on. A 
connexion between certain actions of the domesticated animals, 
and certain atmospheric changes, has been observed and regis- 
tered from time immemorial. I do not know the quadruped 
slave that does not occasionally give us warning of them. Have 
you never observed the restlessness, and uneasiness, and the 
occasional starting of the horse you are riding — or the crowding 
of the horses that are at grass to that part of the field where 
the pasture is most luxuriant, and most easily and quickly got 
at? Have you never attended to the intimation which was given 
by the frequent and impatient braying of the ass, and the con- 
tinual shaking of his ears ? 
’Tis time to cock your liay and corn 
When the old donkey blows his horn*. 
When cattle begin to chase each other around the pasture, 
either voluntarily, or in consequence of the persecution of the fly, 
or bellow as they run, — when they assemble together in a corner or 
part of the field, and with their tails against the wind, — or when 
* “ I once noticed,” says Mr. Forster, that a donkey confined in a yard 
near the house on a showery day brayed before every shower, and usually 
some minutes before the rain began to fall. 
