quently
practiced of compounding whole-wheat flour from inferior mill products,
white flour is sometimes adulterated--more commonly, however, in
European countries that in this--with such substances as alum, ground
rice, plaster of Paris, and whiting. Alum is doubtless the most commonly
used of all these substances, for the reason that it gives the bread a
whiter color and causes the flour to absorb and retain a larger amount
of water than it would otherwise hold. This enables the user to make,
from an inferior brand of flour, bread which resembles that made from a
better quality. Such adulteration is exceedingly injurious, as are other
mineral substances used for a similar purpose.

The presence of alum in flour or bread may be detected in the following
way: Macerate a half slice of bread in three or four tablespoonfuls of
water; strain off the water, and add to it twenty drops of a strong
solution of logwood, made either from the fresh chips or the extract.
Then add a large teaspoonful of a strong solution of carbonate of
ammonium. If alum is present, the mixture will change from pink to
lavender blue.

The _Journal of Trade_ gives the following simple mode of testing for
this adulterant: "Persons can test the bread they buy for themselves, by
taking a piece of it and soaking it in water. Take this water and mix it
with an equal part of fresh milk, and if the bread contains alum, the
mixture will coagulate. If a better test is required, boil the mixture,
and it will form perfect clot."

Whiting can be detected by dipping the ends of the thumb and forefinger
in sweet oil and rubbing the flour between them. If whiting is present,
the flour will become sticky like putty, and remain white; whereas pure
flour, when so rubbed, becomes darker in color, but not sticky. Plaster
of Paris, chalk, and other alkaline adulterants may be detected by a few
drops of lemon juice: if either be present, effervescence will take
place.

CHEMISTRY OF BREAD-MAKING.--Good flour alone will not insure good
bread. As much depends upon its preparation as upon the selection of
material; for the very best of flour may be transformed into the poorest
of bread through improper or careless preparation. Good bread cannot be
produced at random. It is not the fruit of any luck or chance, but the
practical result of certain fixed laws and principles to which all may
conform.

The first step in the conversion of flour into bread is to incorporate
wi