26. Secondary Qualities twofold; first, immediately perceivable; secondly, mediately perceivable.
To conclude. Beside those before-mentioned primary qualities in bodies, viz. bulk, figure, extension,number, and motion of their solid parts; all the rest, whereby we take notice of bodies, and distinguish them one from another, are nothing else but several powers in them, depending on those primary qualities;whereby they are fitted, either by immediately operating on our bodies to produce several different ideas in us; or else, by operating on other bodies, so to change their primary qualities as to render them capable of producing ideas in us different from what before they did. The former of these, I think,may be called secondary qualities IMMEDIATELY PERCEIVABLE: the latter, secondary qualities,MEDIATELY PERCEIVABLE.