Money. Down with your dust; deposit the money. To raise or kick up a dust; to make a disturbance or riot: see BREEZE. Dust it away; drink about.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1736 dictionary of canting and thieving slang.
Durham Man * DustmanNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes