etymological question: "jack shit"

[Laurence Horn]

At 10:35 AM -0400 10/10/00, Mark_Mandel at DRAGONSYS.COM wrote:
>My daughter Susannah asks the following. I have looked in the archives to
>no avail.
>
>>>>>>
>some friends of mine are having an argument about the
>etymological origins of "jack," when used as in "he doesn't know
>jack."  others point out the similarity of this construction to
>"jack shit," when used to mean "nothing" -- in fact, you can also
>say "he don't know jack shit."
>
>the question is, where and how did this originate?
>
>i thought some of your dialectologists might know. :)
><<<<<
>
Well, this (Safire-certified) dialectologist isn't at all certain,
although I've written papers about the grammar of "jackshit" and
other squatitives (to borrow Haj Ross and Paul Postal's label for the
class).  As for "jack" tout court, my best guess is the first cite
(of 21!) listed in Farmer & Henley's (1896/1970) _Slang and its
Analogues_:

JACK (old). --1.  A farthing; also (American thieves') a small coin.

citations go back to a 1690 dictionary and a 1714 memoir, but the
only one given in (more or less) full is

1725.  New Cant. Dict. s.v. Jack.  He wou'd not tip me a jack, Not a
farthing wou'd he give me.

This seems like it would yield the appropriate sense as a minimizer,
and the shift from "isn't worth X" to "doesn't know X" is far from
unprecedented and would be facilitated by the loss of transparency of
the coin reference.  As for "jackshit", maybe it's a combination of
the monetary "jack" (cf. not worth a farthing, red cent, plugged
nickel, thin dime, sou,...) and "shit", which is independently
attested as a calibration of how much something is (not) worth.

larry