4. To make the test more certain boil the yarn so colored
in dilute ammonia for 5 m. The artificial coloring matter
will dissolve in ammonia. If this is colored, add hydro-
chloric acid drop by drop until the solution is acid as tested
by blue litmus paper.
5. In this solution now place some fresh white yarn and
boil.
6. Remove and wash in water. If the yarn is colored
the presence of artificial dyes is proved for certain.
AUGUST MENUS 393
To Test for Preservatives in Milk
1. Formaldehyde:
Place in a test tube 3 T of milk and add an equal volume
of concentrated sulphuric or hydrochloric acid, and a piece
of iron alum about the size of a pin head. Mix the liquids
with a gentle rotary motion.
Place the tube in a dish filled with boiling water and
allow to stand 5 m. A purplish color of the mixture shows
the presence of formaldehyde.
2. Borax or Boric Acid:
Dissolve }i t alum in i c water and add 5^ c milk.
Shake vigorously and filter. Pour a part, about i T, of the
filtrate into a test tube and add a few drops of concen-
trated hydrochloric acid.
Dip a piece of turmeric paper into this and dry it over a
gas flame. Place a drop of strong ammonia on the paper.
A cherry red before adding the ammonia and a dark green
or greenish black color after, shows the presence of borax
or boric acid.
To Test for Oleomargarine
1. Melt a small bit of the sample in a spoon, stirring
with a splint of wood. Oleomargarine and renovated butter
sputter and boil noisily without producing foam, while real
butter boils quietly and produces much foam.
2. Fill a test tube half full of skimmed milk, heat and
add I teaspoonful of the sample of butter. Stir with a
splint until the fat melts. Now place the tube in very cold
water or in ice until the fat hardens, stirring all the time.
If the sample is oleo, it will harden in one mass and may be
lifted out on the splint of wood. If it is butter either
fresh or renovated, it solidifies in small particles scattered
all through the milk.
To Test for Cottonseed Oil
I. Add 2 or 3 T Halphen Reagent (prepared by the
druggist) to an equal volume of the suspected oil in a test
tube or small bottle. Heat very carefully to avoid burning
in a vessel of boiling salt water made by dissolving i T salt
in I pt. water. Boil 10-15 m. At the end of that time a
394 LESSONS IN COOKING
distinct reddish color indicates a small amount of cotton
seed oil, a dark red color, a large amount of cotton seed oil.
Before making tests always try the method with a small
amount of the substance being tested for present, so as to
become familiar zvith the color or precipitate produced.
The chemicals, test tubes, filter paper, etc., required in
these tests can be obtained at almost any drug store. An
alcohol lamp can be used as a source of heat if gas is not
available. Further tests are described in Bulletin No. lOO
of the Bureau of Chemistry, U. S. Dept. of Agriculture,
which may be obtained by sending loc (coin) to the Super-
intendent of Documents, Washington, D. C.
Each State has its own laws in regard to adulteration of
foods ; the National laws apply only to food products enter-
ing into interstate commerce. Send to your State Board
of Health or Pure Food Department (at the capitol city)
for your local regulations and reports.
AUGUST MENUS
Monday Lesson 241
BREAKFAST
Page 219
Presented as published in 1912. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
4. To make the test more certain boil the yarn so colored in dilute ammonia for 5 m. The artificial coloring matter will dissolve in ammonia. If this is colored, add hydrochloric acid drop by drop until the solution is acid as tested by blue litmus paper.
5. In this solution now place some fresh white yarn and boil.
6. Remove and wash in water. If the yarn is colored the presence of artificial dyes is proved for certain.
To Test for Preservatives in Milk
1. Formaldehyde:
Place in a test tube 3 T of milk and add an equal volume of concentrated sulphuric or hydrochloric acid, and a piece of iron alum about the size of a pin head. Mix the liquids with a gentle rotary motion.
Place the tube in a dish filled with boiling water and allow to stand 5 m. A purplish color of the mixture shows the presence of formaldehyde.
2. Borax or Boric Acid:
Dissolve }i t alum in i c water and add 5^ c milk. Shake vigorously and filter. Pour a part, about i T, of the filtrate into a test tube and add a few drops of concentrated hydrochloric acid.
Dip a piece of turmeric paper into this and dry it over a gas flame. Place a drop of strong ammonia on the paper. A cherry red before adding the ammonia and a dark green or greenish black color after, shows the presence of borax or boric acid.
To Test for Oleomargarine
1. Melt a small bit of the sample in a spoon, stirring with a splint of wood. Oleomargarine and renovated butter sputter and boil noisily without producing foam, while real butter boils quietly and produces much foam.
2. Fill a test tube half full of skimmed milk, heat and add I teaspoonful of the sample of butter. Stir with a splint until the fat melts. Now place the tube in very cold water or in ice until the fat hardens, stirring all the time. If the sample is oleo, it will harden in one mass and may be lifted out on the splint of wood. If it is butter either fresh or renovated, it solidifies in small particles scattered all through the milk.
To Test for Cottonseed Oil
I. Add 2 or 3 T Halphen Reagent (prepared by the druggist) to an equal volume of the suspected oil in a test tube or small bottle. Heat very carefully to avoid burning in a vessel of boiling salt water made by dissolving i T salt in I pt. water. Boil 10-15 m. At the end of that time a
distinct reddish color indicates a small amount of cotton seed oil, a dark red color, a large amount of cotton seed oil.
Before making tests always try the method with a small amount of the substance being tested for present, so as to become familiar zvith the color or precipitate produced.
The chemicals, test tubes, filter paper, etc., required in these tests can be obtained at almost any drug store. An alcohol lamp can be used as a source of heat if gas is not available. Further tests are described in Bulletin No. lOO of the Bureau of Chemistry, U. S. Dept. of Agriculture, which may be obtained by sending loc (coin) to the Superintendent of Documents, Washington, D. C.
Each State has its own laws in regard to adulteration of foods ; the National laws apply only to food products entering into interstate commerce. Send to your State Board of Health or Pure Food Department (at the capitol city) for your local regulations and reports.
Monday Lesson 241