ter. Make a paste of one teaspoonful of the flour and
an equal amount of water; mix with it one-quarter of a teaspoonful of
the logwood solution; follow this immediately with one-quarter of a
teaspoonful of the ammonium carbonate solution. If alum is present,
the paste will show a lavender or blue color; if absent, the mass will
become pink, fading to a dirty brown. If the result is doubtful, set
the paste aside for several hours, when the colors will show more
plainly.

=Bread.=--Bread should be well baked and not too light or too heavy;
the crust should be light brown and adherent to the substance of the
bread. The center should be of even consistency, spongy, and firm; it
should not pit or be soggy or doughy. The pores or holes should be of
practically the same size throughout.

Exceedingly white, light, or porous bread shows the presence of alum.
It may be detected by means of the solutions already mentioned in the
"logwood" test. Mix one teaspoonful of each solution and add three
ounces (six tablespoonfuls) of water; pour this over a lump of bread,
free from crust and about an inch square. After the bread has become
thoroughly soaked, pour off the excess of liquid and dry the bread in
the dish; if alum is present, the mass will show a violet or blue
tint, more marked on drying; if absent, a brownish color will appear.

=Baking Powders.=--Baking powders are of three classes, all having
sodium bicarbonate (baking soda) as their alkaline salt. The first
style is the commonly used and wholesome mixture of cream of tartar
and baking soda; the second has calcium phosphate for the acid salt,
and the third contains alum. All have a certain proportion of starch
to absorb moisture. Of these the alum powders are the most harmful and
should be avoided. Practically all of the well-known brands of baking
powder are of the first-mentioned class and wholesome, and are rarely
adulterated.

=DAIRY PRODUCTS--Milk.=--Pure milk should have a specific gravity of
from 1.027 to 1.033. Its normal reaction is neutral or slightly acid;
it should never be strongly acid. If it is strongly alkaline, i. e.,
turning red litmus paper blue, it is pretty certain that something in
the way of a preservative has been added to it. When left standing for
a few hours the cream should show as a slightly yellowish top layer,
one-tenth or more of the whole amount; the milk below the cream should
be lighter in color and with the slightest bluish tinge.