Green’s Dictionary of Slang

a banknote, usu. defined as to its amount, e.g. a £10 Henry Hase.

1819		Beppo in London lxxxv: They easily procur’d admission, By off’ring up their little Henry Hases.
1820		W.T. Moncrieff Collegians A twenty pound Henry Hase.
1824		Egan Boxiana IV 652: When to pass on the whip-hand makes his tender in browns, or glistner, Harry Hase or bender.