[pjt33]

Originally Posted by Perikles

Yes, that would indeed have been difficult to figure that out, since she was responding to my bid, not an opponent's bid.

Oops.

Update: a bit of digging with Wikipedia led to [1], which describes an early whist variant which evolved into bridge. It already had no trumps, under the name "biritch", counting higher than spades in 1886. So the mystery remains.

[1] http://en.wikisource.org/wiki/Biritch,_or_Russian_Whist