10. Secondary qualities of bodies.
Secondly, such qualities which in truth are nothing in the objects themselves
but power 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, tastes, 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 consistency, 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.
