Richard Brinsley Sheridan died (7-7-1816)

Anglo-Irish playwright (and politician).
Crystal's linguistic point is Sheridan's _The Critic_ (1779) "a parody of theatre writing and practices", in which the character Mr.Puff describes himself as "a practitioner in panegyric, or, to speak more plainly, a professor of the art of puffing, at your service."
Just in case this word is not familiar, a puff is/was "a piece of inflated or unmerited praise, used to advertise a product, or, in this case, to advertise a play." [Crystal]
"an empty or idle boast; bombast, inflation of style, ‘hot air’; vanity, pride; showy adornment." [OED, from 1567]
He quotes a long paragraph of Mr Puff puffing himself, claiming that he taught the greatest puffers (here - auctioneers) everything they know.
https://en.wikipedia.org/wiki/Richard_Brinsley_Sheridan