Supposing the nominal essence of Gold, to be body of such a peculiar Colour and Weight, with Malleability and Fusibility, the real Essence is that constitution of the
parts of Matter, on which these qualities, and their Union, depend; and is also the
foundation of its solubility in Aqua Regia, and other Properties accompanying that
complex Idea … Nor indeed can we rank, and sort Things, and consequently (which
is the end of sorting) denominate them by their real Essences, because we know them
not. Our Faculties carry us no farther towards the knowledge and distinction of
substances, than a collection of those sensible Ideas, which we observe in them