The Collaborative International Dictionary of English v.0.48:

Bordeaux mixture \Bor*deaux" mix"ture\ (Hort.)
   A fungicidal mixture composed of blue vitriol, lime, and
   water. The formula in common use is: blue vitriol, 6 lbs.;
   lime, 4 lbs.; water, 35 -- 50 gallons.
   [Webster 1913 Suppl.] Bordel

WordNet (r) 3.0 (2006):

Bordeaux mixture
    n 1: antifungal agent consisting of a solution of copper
         sulphate and quicklime