Oliver Twist - Victorian novel by Charles Dickens.
Rum as prefix to slang words has nothing to do with the drink. The Oxford English Dictionary describes rum prefix as a canting term from the criminal underworld. To start with it was positive, meaning variously good, fine, excellent or great. Subsequently "rum booze" was fine or excellent drink, a rum duke was a handsome man and a rum dab was a dextrous thief (dabs are fingers), rum bugher was a valuable nifty working hound, often as criminal as their masters (poachers/thieves), but it was cant from within the criminal world where a duke was not a toff/aristocrat, he was a master mind of criminal activity, and this is where modern-day writers have researched the wrong elements of the rum prefix re periods in history.
Do you remember Oliver Reed as Dodger in Oliver Twist and his "rum bugher" Bullseye (Dickens).
Around 1800 the word "rum" prior to a word (prefix) appeared to do a flip from positive to negative and started to mean something that was odd, strange or peculiar. A rum book was a curious or strange one, a rum customer was a peculiar man or one risky to offend, a rum phiz was an odd face and so on.
The OED guesses (it would be fair to say) the change came about when old criminal cant slid into common usage, through slang expressions such as rum cove, originally "an excellent or first-class rogue".
Other terms also shifted their senses over time - subsequently the English Dialect/Cant Dictionary noted rum duke was “a strange, unaccountable person”, a substantial shift in sense from the original, because it no longer referred to the criminal duke, or criminal activities. But the original cant continued within the criminal underworld.
Dozens of slang terms were cleaned up, became commonplace
rum do - definition: a strange situation or event
rum deal -def - raw deal
rum bugger - true def - sodomise/er - cant - derogatory term for slippery/untrustworthy character.
rum bum - def - runny/grassy poo
So if you're writing Georgian period/Regency cant, rum prefix tended negative/derogatory at a time when the Bow Street Runners came into being. How much the BSR influenced the switch in cant bears scrutiny. Which brings us to cant, which tended to be in use within the working realms of society and rarely used within the drawing rooms and salons of the social elite, where a word of that nature would not only raise eyebrows it would give rise to mistrusting the speaker!
And of course Francis Grose's Dictionary of the Vulgar Tongue takes you into the backstreet dives and dens of the criminal world cant, not to mention bawdy houses and doxy madams. The BBC looks at Francis' life and how he acquired the listings for his dictionary.