hinder Bodies there from rising up and going
away from the Sun in the form of Vapours and Fumes, unless by means of a
far greater heat than that which on the Surface of our Earth would very
easily turn them into Vapours and Fumes. And the same great weight may
condense those Vapours and Exhalations as soon as they shall at any time
begin to ascend from the Sun, and make them presently fall back again
into him, and by that action increase his Heat much after the manner
that in our Earth the Air increases the Heat of a culinary Fire. And the
same weight may hinder the Globe of the Sun from being diminish'd,
unless by the Emission of Light, and a very small quantity of Vapours
and Exhalations.

_Qu._ 12. Do not the Rays of Light in falling upon the bottom of the Eye
excite Vibrations in the _Tunica Retina_? Which Vibrations, being
propagated along the solid Fibres of the optick Nerves into the Brain,
cause the Sense of seeing. For because dense Bodies conserve their Heat
a long time, and the densest Bodies conserve their Heat the longest, the
Vibrations of their parts are of a lasting nature, and therefore may be
propagated along solid Fibres of uniform dense Matter to a great
distance, for conveying into the Brain the impressions made upon all the
Organs of Sense. For that Motion which can continue long in one and the
same part of a Body, can be propagated a long way from one part to
another, supposing the Body homogeneal, so that the Motion may not be
reflected, refracted, interrupted or disorder'd by any unevenness of the
Body.

_Qu._ 13. Do not several sorts of Rays make Vibrations of several
bignesses, which according to their bignesses excite Sensations of
several Colours, much after the manner that the Vibrations of the Air,
according to their several bignesses excite Sensations of several
Sounds? And particularly do not the most refrangible Rays excite the
shortest Vibrations for making a Sensation of deep violet, the least
refrangible the largest for making a Sensation of deep red, and the
several intermediate sorts of Rays, Vibrations of several intermediate
bignesses to make Sensations of the several intermediate Colours?

_Qu._ 14. May not the harmony and discord of Colours arise from the
proportions of the Vibrations propagated through the Fibres of the
optick Nerves into the Brain, as the harmony and discord of Sounds arise
from the proportions of the Vibrations of the Air? For some Colours, if
they be vi