Green’s Dictionary of Slang

the end of the nightly performance at the Theatres-Royal, London; as the crowds disperse pickpockets move among them looking for valuables.

1812		Vaux Vocab. of the Flash Lang.
1821		Egan Life in London (1904) 143: tom is sluicing the ivory of some of the unfortunate heroines with blue ruin, whom the breaking-up of the spell has turned-up without any luck.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.