e increased sensation
of heat. See Class I. 1. 2. 1. and 3.

8. _Rubor jucunditatis._ The blush of joy is owing to the increased action
of the capillary arteries, along with that of every moving vessel in the
body, from the increase of pleasurable sensation.

9. _Priapismus amatorius._ Amatorial priapism. The blood is poured into the
cells of the corpora cavernosa much faster than it can be reabsorbed by the
vena penis, owing in this case to the pleasurable sensation of love
increasing the arterial action. See Class I. 1. 4. 6.

10. _Distentio mamularum._ The teats of female animals, when they give
suck, become rigid and erected, in the same manner as in the last article,
from the pleasurable sensation of the love of the mother to her offspring.
Whence the teat may properly be called an organ of sense. The nipples of
men do the same when rubbed with the hand. See Class I. 1. 4. 7.

* * * * *

ORDO II.

_Decreased Sensation._

GENUS I.

_Of the General System._

SPECIES.

1. _Stultitia insensibilis._ Folly from insensibility. The pleasure or pain
generated in the system is not sufficient to promote the usual activity
either of the sensual or muscular fibres.

2. _Taedium vitae._ Ennui. Irksomeness of life. The pain of laziness has
been thought by some philosophers to be that principle of action, which has
excited all our industry, and distinguished mankind from the brutes of the
field. It is certain that, where the ennui exists, it is relieved by the
exertions of our minds or bodies, as all other painful sensations are
relieved; but it depends much upon our early habits, whether we become
patient of laziness, or inclined to activity, during the remainder of our
lives, as other animals do not appear to be affected with this malady;
which is perhaps left owing to deficiency of pleasurable sensation, than to
the superabundancy of voluntary power, which occasions pain in the muscles
by its accumulation; as appears from the perpetual motions of a squirrel
confined in a cage.

3. _Paresis sensitiva._ Weakness of the whole system from insensibility.

* * * * *

ORDO II.

_Decreased Sensation._

GENUS II.

_Of Particular Organs._

SPECIES.

1. _Anorexia._ Want of appetite. Some elderly people, and those debilitated
by fermented liquors, are liable to lose their appetite for animal food;
which is probably in part owing to the deficiency of gas