nature, have effects in every
way opposite to the former, as is evident in the case of burnings and
cuttings of the body.

Thus have we discussed the general affections of the whole body, and
the names of the agents which produce them. And now I will endeavour to
speak of the affections of particular parts, and the causes and agents
of them, as far as I am able. In the first place let us set forth what
was omitted when we were speaking of juices, concerning the affections
peculiar to the tongue. These too, like most of the other affections,
appear to be caused by certain contractions and dilations, but they
have besides more of roughness and smoothness than is found in other
affections; for whenever earthy particles enter into the small veins
which are the testing instruments of the tongue, reaching to the heart,
and fall upon the moist, delicate portions of flesh--when, as they
are dissolved, they contract and dry up the little veins, they are
astringent if they are rougher, but if not so rough, then only harsh.
Those of them which are of an abstergent nature, and purge the whole
surface of the tongue, if they do it in excess, and so encroach as to
consume some part of the flesh itself, like potash and soda, are all
termed bitter. But the particles which are deficient in the alkaline
quality, and which cleanse only moderately, are called salt, and having
no bitterness or roughness, are regarded as rather agreeable than
otherwise. Bodies which share in and are made smooth by the heat of
the mouth, and which are inflamed, and again in turn inflame that which
heats them, and which are so light that they are carried upwards to the
sensations of the head, and cut all that comes in their way, by reason
of these qualities in them, are all termed pungent. But when these same
particles, refined by putrefaction, enter into the narrow veins, and
are duly proportioned to the particles of earth and air which are there,
they set them whirling about one another, and while they are in a whirl
cause them to dash against and enter into one another, and so form
hollows surrounding the particles that enter--which watery vessels of
air (for a film of moisture, sometimes earthy, sometimes pure, is spread
around the air) are hollow spheres of water; and those of them which are
pure, are transparent, and are called bubbles, while those composed
of the earthy liquid, which is in a state of general agitation and
effervescence, are said to boil