There can be no doubt that bodies which are rough and angular, rouse and vellicate the organs of feeling, causing a sense of pain, which consists in the violent tension or contraction of the muscular fibres.

On the contrary, the application of smooth bodies relaxes; gentle stroking with a smooth hand allays violent pains and cramps, and relaxes the suffering parts from their unnatural tension; and it has therefore very often no mean effect in removing swellings and obstructions.

The sense of feeling is highly gratified with smooth bodies.

A bed smoothly laid, and soft, that is, where the resistance is every way inconsiderable, is a great luxury, disposing to an universal relaxation, and inducing beyond anything else that species of it called sleep.
SECTION XXI.
SWEETNESS, ITS NATURE.
Nor is it only in the touch that smooth bodies cause positive pleasure by relaxation.

In the smell and taste, we find all things agreeable to them, and which are commonly called sweet, to be of a smooth nature, and that they all evidently tend to relax their respective sensories.