Bath, n. — Green’s Dictionary of Slang

Bath n.

Proper name in slang uses

In phrases

go to Bath (v.) [the rich pickings that were supposedly to be obtained from Bath’s fashionable wealthy population. Bath, with its spas, attracted the mad as well as the rich and their parasites]

to take up life as a beggar; thus excl. go to Bath (and get your head shaved!) go away, you’re insane!

[1588		W. Lambard Office of the Justices of the Peace 334: Such two Justices may... License diseased persons (living on almes) to travell to Bathe, or to Buckstone [Buxton], for remedie of their griefe [F&H]].
1837		‘Terence O’Shaughnessy’ in Bentley’s Misc. Jan. 41: What do you think, Terence, was his reply? Why, that Miss Mac Teggart might go to Bath, for he would have no call to my swivel-eyed customers.
1885		Frank Leslie’s Illus. Newspaper 16 Oct. 362: You tell a disagreeable neighbour to go to Bath in the sense in which a Roman would have said abi in malam rem [F&H].
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant I 422/2: Go to Bath and get your head shaved. This phrase denotes mental disorder, and as the waters of Bath were formerly in good repute for the cure of mental derangements, the saying implied that the person so addressed was silly or idiotic, and should pro bono publico do something to get cured.
1894		E.W. Rogers [perf. Vesta Tilley] The End of the Song 🎵 ‘Go to Bath? all right, old ducky / Thank you kindly, do the same!’.
1933		Taunton Courier 26 Apr. 10/3: The saying ‘Go to Putney on a Pig’ once meant ‘Go to Putney in a basin or bowl,’ [and] reminds me that my grandmother used to sday ‘Go to Bath — in a bowl dish’.