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CHAP. IV

1. Of greater Moment in the Investigation of the Nature of Colours is the
Controversie, Whether those of the Rain-bow, and those that are often seen
in Clouds, before the Rising, or after the Setting of the Sun; and in a
word, Whether those other Colours, that are wont to be call'd Emphatical,
ought or ought not to be accounted True Colours. I need not tell you that
the Negative is the Common Opinion, especially in the Schools, as may
appear by that Vulgar distinction of Colours, whereby these under
Consideration are term'd Apparent, by way of Opposition to those that in
the other Member of the Distinction are call'd True or Genuine. This
question I say seems to me of Importance, upon this Account, that it being
commonly Granted, (or however, easie enough to be Prov'd) that Emphatical
Colours are Light it self Modify'd by Refractions chiefly, with a
concurrence sometimes of Reflections, and perhaps some other Accidents
depending on these two; if these Emphatical Colours be resolv'd to be
Genuine, it will seem consequent, that Colours, or at least divers of them,
are but Diversify'd Light, and not such Real and Inherent qualities as they
are commonly thought to be.

2. Now since we are wont to esteem the Echoes and other Sounds of Bodies,
to be True Sounds, all their Odours to be True Odours, and (to be short)
since we judge other Sensible Qualities to be True ones, because they are
the proper Objects of some or other of our Senses, I see not why Emphatical
Colours, being the proper and peculiar Objects of the Organ of Sight, and
capable to Affect it as Truly and as Powerfully as other Colours, should be
reputed but Imaginary ones.