a secondary sympathy the
membranes about the ear and temple became torpid, and painful; and those of
the alveolar process of the upper jaw regained their natural quantity of
action, and ceased to be painful. A great many more nice and attentive
observations are wanted to elucidate these curious circumstances of
association, which will be found to be of the greatest importance in the
cure of many diseases, and lead us to the knowledge of fever.

SPECIES.

1. _Cutis frigida pransorum._ Chillness after dinner frequently attends
weak people, or those who have been exhausted by exercise; it arises from
the great expenditure of the sensorial power on the organs of digestion,
which are stimulated into violent action by the aliment; and the vessels of
the skin, which are associated with them, become in some measure torpid by
reverse sympathy; and a consequent chillness succeeds with less absorption
of atmospheric moisture. See the subsequent article.

2. _Pallor urinae pransorum._ The paleness of urine after a full meal is an
instance of reverse association; where the secondary part of a train of
associate motions acts with less energy in consequence of the greater
exertions of the primary part. After dinner the absorbent vessels of the
stomach and intestines are stimulated into greater action, and drink up the
newly taken aliment; while those, which are spread in great number on the
neck of the bladder, absorb less of the aqueous part of the urine than
usual, which is therefore discharged in a more dilute state; and has been
termed crude by some medical writers, but it only indicates, that so great
a proportion of the sensorial power is expended on digestion and absorption
of the aliment, that other parts of the system act for a time with less
energy. See Class IV. I. 1. 6.

3. _Pallor urinae a frigore cutaneo._ There is a temporary discharge of
pale water, and a diarrhoea, induced by exposing the skin to the cold air;
as is experienced by boys, who strip themselves before bathing. In this
case the mouths of the cutaneous lymphatics become torpid by the subduction
of their accustomed degree of heat, and those of the bladder and intestines
become torpid by direct sympathy; whence less of the thinner part of the
urinary secretion, and of the mucus of the intestines, is reabsorbed. See
Sect. XXIX. 4. 6. This effect of suddenly cooling the skin by the aspersion
of cold water has been used with success in costiveness, and has pr