Green’s Dictionary of Slang

(Aus./UK/US Und.) a policeman.

1821		N.-Y. Eve. Post 21 Aug. 2/1: They shall be driven away by the ‘Blue devils’ to seek pleasure in some other quarter.
1833		‘The Chummies’ Society’ in Fun Alive O! 55: A pair of blue devils came in / And hiked us both to the roundakin.
1834		Satirist (London) 12 Jan. 15/3: The new police - the blue devil corps - the ‘raw lobsters,’ are the subject of the book.
1835		Duncombe Dens of London 47: A slap on my shoulder, with ‘what do you want there?’ made me turn round; and there I met the ugly mug of a devil in blue.
1841		‘Poll Newry, The Dainty Flag-Hopper’ in Gentleman’s Spicey Songster 34: The raw lobsters she sets at defiance, / She tips ’em a bit of her science; / Like a boxer she floors, the blue devils by scores, / And then in a crack she will fly hence.
1846		Bell’s Life in Sydney 20 June 3/2: The intervention of a blue devil checked the career of the red fugitive who was consigned to durance.
1848		Sinks of London Laid Open 44: I laughed at them and still tried it on, when one of them called to a blue devil, ‘Take this fellow into custody.’.
1877		‘Wasn’t It Very Polite of Her?’ in Laughing Songster 154: Two lanky blue devils did collar me.
1913		Yorks. Post 29 Aug. 7/5: The writer substitutes the words ‘policeman’ and ‘police’ for ‘bluebottles’ and ‘blue devils’.