her
parts of the body, by ways equally as unknown, should be thought to
exist in the manna, when they are not seen or tasted, would need some
reason to explain.

19. Examples.

Let us consider the red and white colours in porphyry. Hinder light from
striking on it, and its colours vanish; it no longer produces any such
ideas in us: upon the return of light it produces these appearances
on us again. Can any one think any real alterations are made in the
porphyry by the presence or absence of light; and that those ideas of
whiteness and redness are really in porphryry in the light, when it is
plain IT HAS NO COLOUR IN THE DARK? It has, indeed, such a configuration
of particles, both night and day, as are apt, by the rays of light
rebounding from some parts of that hard stone, to produce in us the idea
of redness, and from others the idea of whiteness; but whiteness or
redness are not in it at any time, but such a texture that hath the
power to produce such a sensation in us.

20. Pound an almond, and the clear white colour will be altered into a
dirty one, and the sweet taste into an oily one. What real alteration
can the beating of the pestle make in an body, but an alteration of the
texture of it?

21. Explains how water felt as cold by one hand may be warm to the other.

Ideas being thus distinguished and understood, we may be able to give an
account how the same water, at the same time, may produce the idea of
cold by one hand and of heat by the other: whereas it is impossible that
the same water, if those ideas were really in it, should at the same
time be both hot and cold. For, if we imagine WARMTH, as it is in our
hands, to be nothing but a certain sort and degree of motion in the
minute particles of our nerves or animal spirits, we may understand how
it is possible that the same water may, at the same time, produce the
sensations of heat in one hand and cold in the other; which yet FIGURE
never does, that never producing the idea of a square by one hand which
has produced the idea of a globe by another. But if the sensation of
heat and cold be nothing but the increase or diminution of the motion of
the minute parts of our bodies, caused by the corpuscles of any other
body, it is easy to be understood, that if that motion be greater in one
hand than in the other; if a body be applied to the two hands, which has
in its minute particles a greater motion than in those of one of the
hands, and a less than