"urine" with long "i"

[Douglas G. Wilson]

>"Taking the piss", aka "Taking the mickey/michael" or "Extracting
>the urine"*, means "Making fun off, usually (but not necessarily)
>with an attitude of contempt".
>
>*(which, in that context, is always pronounced "Yur-eye-n", even
>if you normally prefer "Yur-inn" - Dunno why, just is)

I refer to Cassell's slang dictionary.

"Mickey"/"Michael" apparently is rhyming slang ("Mickey Bliss") for "piss".

"Extracting the Michael/urine" is apparently a consciously prissy/genteel
elaboration/euphemism for "taking the piss [out of someone]". I think the
odd pronunciation of "urine" is explained by this interpretation, the user
lacking (or pretending to lack) "urine" in his usual speaking vocabulary.

What is the original sense of "taking the piss [out of ...]" = "tease"? Is
it parallel to "beating the piss out of someone"? Or to "taking the starch
out of someone"? Or does it actually refer to urethral catheterization
(which may have been more familiar to the 'common man' in the days before
successful antibiotic treatment of venereal diseases)?

Is there any connection with "pulling someone's
leg/tit/tail/chain/cock/pisser" = "teasing someone"?

-- Doug Wilson