— 519 —
Ideas of the leading Qualities of Substances, are best got by shewing.
      §21. Now these leading Qualities, are best made known by shewing, and
can hardly be made known otherwise. For the shape of an Horse, or
Cassuary, will be but rudely and imperfectly imprinted on the Mind
by Words, the sight of the Animals doth it a thousand times
better: And the Idea of the particular Colour of Gold, is not to be got
by any description of it, but only by the frequent exercise of the
Eyes about it; as is evident in those who are used to this Metal, who
will frequently distinguish true from counterfeit, pure from adul-
terate, by the sight, where others, (who have as good Eyes, but yet,
by use, have not got the precise nice Idea of that peculiar Yellow)
shall not perceive any difference. The like may be said of those other
simple Ideas, peculiar in their kind to any Substance; for which
precise Ideas, there are no peculiar Names. The particular ringing
sound there is in Gold, distinct from the sound of other Bodies, has
no particular Name annexed to it, no more than the particular
Yellow, that belongs to that Metal.
Locke Hum III, 11, §21, p. 519