Page:Observations on Man 1834.djvu/107

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CHAP. II.

CONTAINING THE APPLICATION OF THE DOCTRINES OF VIBRATIONS AND ASSOCIATION TO EACH OF THE SENSATIONS AND MOTIONS, IN PARTICULAR.

Section I

OF THE SENSE OF FEELING.


Prop. XXIII.—To distinguish the several Kinds of Feeling from each other, and to assign the general Causes of the different Degrees of Exquisiteness in this Sense.


Here we may first distinguish feeling into the general and particular.

The general feeling extends to all the parts of the body, external and internal: for they are all susceptible of pain from wounds and inflammations, of being put into a pleasurable state, of numbness, and total want of sensation, and of perceiving heat, cold, and pressure. Some writers consider all the sensations of all the senses as so many kinds of feeling; but I do not here use this word in so extensive an acceptation.

The particular feeling is that more exquisite degree which resides in the insides of the hands, and especially in the ends of the fingers; and by which we distinguish the tangible qualities of bodies, viz. heat, cold, moisture, dryness, softness, hardness, smoothness, roughness, also their motion, rest, distance, and figure, with more accuracy than by any other part. These sensations are, for the most part, adiaphorous ones.

The greater exquisiteness of the particular feeling arises probably from the following causes:

First, The sentient papillæ rise high from the skin (becoming extreme parts thereby), and receive a large proportional quantity of nerves in the ends of the fingers.

Secondly, The ends of the fingers are themselves extreme parts, and consequently receive stronger agitations in their infinitesimal medullary particles, from the stronger vibrations of the