9. Their powers usually make up our complex ideas of substances.
Whosoever first lighted on a parcel of that sort
of substance we denote by the word gold, could not rationally take the bulk and figure he observed in that lump to
depend on its real essence, or internal constitution. Therefore those never went into his idea of that species of
body; but its peculiar colour, perhaps, and weight, were the first he abstracted from it, to make the complex idea
of that species. Which both are but powers; the one to affect our eyes after such a manner, and to produce in us
that idea we call yellow; and the other to force upwards any other body of equal bulk, they being put into a pair of
equal scales, one against another. Another perhaps added to these the ideas of fusibility and fixedness, two other
passive powers, in relation to the operation of fire upon it; another, its ductility and solubility in aqua regia, two
other powers, relating to the operation of other bodies, in changing its outward figure, or separation of it into
insensible parts. These, or parts of these, put together, usually make the complex idea in men's minds of that sort
of body we call gold.
