No discoverable necessary connexion between nominal essence gold, and other simple ideas.
As there is no discoverable connexion between fixedness and the colour, weight, and other simple ideas of that nominal essence of gold; so, if we make our complex idea of gold, a body yellow, fusable, ductile, weighty, and fixed, we shall be at the same uncertainty concerning solubility in AQUA REGIA, and for the same reason.

Since we can never, from consideration of the ideas themselves, with certainty affirm or deny of a body whose complex idea is made up of yellow, very weighty, ductile, fusible, and fixed, that it is soluble in AQUA REGIA: and so on of the rest of its qualities.

I would gladly meet with one general affirmation concerning any will, no doubt, be presently objected, Is not this an universal proposition, ALL GOLD IS MALLEABLE?
To which I answer, It is a very complex idea the word gold stands for.

But then here is nothing affirmed of gold, but that that sound stands for an idea in which malleableness is contained: and such a sort of truth and certainty as this it is, to say a centaur is four-footed.

But if malleableness make not a part of the specific essence the name of gold stands for, it is plain, ALL GOLD IS MALLEABLE, is not a certain proposition.