E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
or Essay. To take the assay is to taste wine to prove it is not poisoned. Hence, to try, to taste; a savour, trial, or sample. Holinshed says, Wolsey made dukes and earls serve him of wine with a say taken (p. 847).
Edmund, in King Lear (v. 5), says to Edgar, Thy tongue, some say of breeding breathes; i.e. thy speech gives indication of good breedingit savours of it. Hence the expression, I make my first assay (trial).