— 135 —
      §10. 2dly, Such Qualities, which in truth are nothing in the
Objects themselves, but Powers to produce various Sensations in us
by their primary Qualities, i.e. by the Bulk, Figure, Texture, and
Motion of their insensible parts, as Colours, Sounds, Tasts, etc.
These I call secondary Qualities. To these might be added a third sort
which are allowed to be barely Powers though they are as much
real Qualities in the Subject, as those which I to comply with the
common way of speaking call Qualities, but for distinction secondary
Qualities. For the power in Fire to produce a new Colour, or con-
sistency in Wax or Clay by its primary Qualities, is as much a
quality in Fire, as the power it has to produce in me a new Idea or
Sensation of warmth or burning, which I felt not before, by the
same primary Qualities, viz. The Bulk, Texture, and Motion of its
insensible parts.
Locke Hum II, 8, §10, p. 135