There are two kinds cultivated, the black and the white, annuals, and
natives of Great Britain. The white mustard is cultivated in this
country principally for greens, and sometimes for a small salad like the
cress. It may be sown at any time from opening of spring to the
beginning of autumn. But sown in hot weather, the bed must be shaded.
The Spaniards prefer the white mustard for grinding for table use,
because of its mildness and its whiter flour. White mustard-seed, being
much larger than the black, is preferred for mangoes, and all pickling
purposes.
Black mustard is cultivated principally in the field, for the mills. It
is there ground, and makes the well known condiment found on most
tables.
Sow in March or April, broadcast on land tolerably free from weeds, and
if you get it too thick, hoe up a part. In July or August, you may get a
good crop. Cradle it as wheat, before ripe enough to shell.
Mustard used in various ways is medicinal. It is one of the safest and
most speedy emetics. Stir up a table-spoonful of the flour and drink it.
Follow it with repeated draughts of warm water, and in half an hour, you
will have gone through all the stages of a thorough emetic, without
having been weakened by it.