Green’s Dictionary of Slang

smithers n.

[Lincolnshire dial. smithers, fragments, shivers; ult. ? SE smite, to smash]

tiny fragments, atoms.

Tennyson Northern Cobbler xviii n.p.: ‘Smash the bottle to smithers, the Divil’s in ’im,’ said I [F&H].
[UK]Hotten Dict. of Modern Sl. etc. (2nd edn).