from
The Collaborative International Dictionary of English v.0.48
Oxalic \Ox*al"ic\, a. [From {Oxalis}: cf. F. oxalique.] (Chem.)
Pertaining to, derived from, or contained in, sorrel, or
oxalis; specifically, designating an acid found in, and
characteristic of, oxalis, and also certain plant of the
Buckwheat family.
[1913 Webster]
{Oxalic acid} (Chem.), a dibasic acid ({HO.CO.CO.OH}),
existing combined in oxalis as an acid potassium oxalate,
and in many plant tissues as the calcium oxalate. It is
prepared on a large scale, by the action of fused caustic
soda or potash on sawdust, as a white crystalline
substance, which has a strong acid taste, and is poisonous
in large doses. It is used in dyeing, calico printing,
bleaching flax and straw, the preparation of formic acid,
and in salts of lemon for removing ink stains, mold, etc.
[1913 Webster]