In addition to these authorities in favour of a singular usage, it may be observed, that the word much, a term of quantity, not of number, is frequently joined with it, as,
“I found much art and pains employed.”—Middleton.
“He will assemble materials with much pains.”—Bolingbroke on History.
The word much is never joined to a plural noun; much labours, much papers, would be insufferable[13].
Riches is generally now considered as a plural noun; though it was formerly used either as singular or plural. This substantive seems to have been nothing but the French word richesse; and therefore no more a plural than gentlenesse, distresse, and many others of the same kind. In this form we find it in Chaucer:
“But for ye spoken of swiche gentlenesse,
As is descended out of old richesse.
And he that ones to love doeth his homage,
Full often times dere bought is the richesse.”
Accordingly he gives it a plural termination, and uses it as a plural word.