The Science Notebook
Gilbert Chemistry - Part 7

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NOTE:  This book was published in 1936 as a manual to accompany several Gilbert Chemistry sets of the time.  While some of the experiments and activities here may be safely done as written, a number of them use chemicals and methods no longer considered safe.  In addition, much of the information contained in this book about chemistry and other subjects is outdated and inaccurate.  Therefore, this book is probably best appreciated for its historical value rather than as a source for current information and good experiments.  If you try anything here, please understand that you do so at your own risk.  See our Terms of Use.

Pages 121 - 140


oil which keeps the lacquer film tough and pliable. Large numbers of new solvents and resins have been synthesized in the last few years, making possible lacquers of almost endless variations in properties.
EXPERIMENT 314 - Making a water color medium or vehicle
Cover two measures of gum arabic in a beaker or cup with about five test tubes of water and let it stand still about a day. On stirring with a stirring rod you will find that you have a thin gummy liquid or mucilage. This material when mixed with a colored powder makes a very good water color paint and, when dry after being painted on a surface, adheres to the surface and has a glossy finish. If it is to be kept long, a drop or two of a preservative such as carbolic acid must be added.

EXPERIMENT 315 - To make a color lake
Lakes are colored bodies made by precipitating a colloid which is a jelly-like substance in the presence of an organic dye, the dye being absorbed by the colloid and giving it color.

To make a purple lake, put two measures of logwood in a test tube half full of water and boil for several minutes. Add one and a half measures of aluminum sulphate and shake the mixture thoroughly. Allow the test tube to stand for several minutes and pour the clear red liquid into another test tube. Now add to this solution one measure of sodium carbonate and shake the mixture. Notice the formation of a deep purple precipitate. Collect this precipitate in a funnel with filter paper.  This purple lake can be mixed with your water color vehicle to make it good water color paint.

EXPERIMENT 316 - To make a carmine lake

Follow the directions of the previous experiment, but substitute two measures of cochineal in place of the logwood.

EXPERIMENT 317 - To make a black lake
Folow the directions for the purple lake, but in place of aluminum sulphate use one and a half measures of ferrous ammonium sulphate.  Collect the black precipitate and mix it with a few drops of the gum arabic solution to make a good black water paint.

Colored organic substances which are not lakes may be useful pigments. The following are examples.

EXPERIMENT 319 - A black charcoal paint
Mix together three or four measures of powdered charcoal with two or three drops pf gum arabic solution. This gives a black charcoal paint.

EXPERIMENT 319 - A black iron paint
Mix together one measure of ferric ammonium sulphate, one measure of tannic acid, and two or three drops of gum arabic solution.  The black color is due to black iron tannate.

The most common class of pigments consists of insoluble inorganic substances, generally called mineral pigments.

EXPERIMENT 320 - White terra alba paint

Mix well together three or four drops of gum arabic solution and four or five measures of calcium sulphate.  This white water color paint is commonly called terra alba or mineral white.


EXPERIMENT 321 - Paris white
Substitute calcium carbonate (whiting) in the directions of the previous experiment.
EXPERIMENT 322 - To make zinc white
Put four or five measures of powdered zinc in the spoon and oxidize it by heating it carefully over a flame. When the zinc has turned to a white powder, allow it to cool and pulverize it very fine. This pigment may then be moistened with your gum arabic solution to give you a paint.

EXPERIMENT 323 - To make Prussian blue
First dissolve three measures of sodium ferrocyanide in a test tube 1/3 full of water.  In another test tube 1/3 full of water dissolve three measures of ferric ammonium sulphate.  Mix these solutions, and collect the deep blue precipitate on a f1lter.  By mixing it with gum arabic solution you obtain Prussian blue paint.

EXPERIMENT 324 - A brown iron paint
Dissolve one measure of sodium carbonate in a test tube 1/4 full of water.  In the same quantity of water in another tube dissolve one measure of ferric ammonium sulphate. The red~brown precipitate which forms is ferric hydroxide and may be filtered out and used as a pigment in gum arabic solution.

EXPERIMENT 325 - A black manganese paint
Moisten three or four measures of manganese dioxide with gum arabic solution.

EXPERIMENT 326 - A white wash
Mix four or five measures of calcium oxide with five or six drops of water until a smooth paste is obtained. It may be used in this form as a cheap whitewash, but it is improved by addition of a binder such as gum arabic or glue solution.

EXPERIMENT 327-Melting a lacquer vehicle
Obtain some waste celluloid, such as used photograph films.  Fill a bottle 1/4 full of scrap celluloid and fill nearly full with acetone an put in a stopper.  Let stand for a time and shake occasionally until celluloid is entirely dissolved.  If you use photograph films you can make them dissolve more quickly if you first remove the coating of gelatin by a wash with hot water containing a little sodium carbonate.  When the celluloid has gone into solution in the acetone, pour the clear solution into another bottle, leaving behind any undissolved sediment.  Add as a plasticizer a few drops of castor oil.  You now have a very useful clear lacquer which you can use to protect bottle labels, to coat polished metals to keep them bright, etc.  But it may also be mixed with colored powders to produce very useful colored lacquers.

EXPERIMENT 328-An aluminum lacquer
Moisten a few measures of fine aluminum powder with this lacquer vehicle. You will obtain a water-proof aluminum lacquer.

EXPERIMENT 329-A black lacquer
Pulverize a few measures of charcoal to a very fine powder, or obtain some in the form of lampblack.  Before trying to mix it with the clear lacquer, it will help if you stir in a drop or two of acetone - just enough to barely moisten it.  Now stir it up with enough clear lacquer to make it thin enough to spread with a brush.

The procedure of the two experiments above may be followed with any of the dry pigments you have used for water paints. However, if the pigment is wet, as was


the case with several that you prepared from water solution by precipitation, you must first remove the water before using the pigment in a lacquer. The following experiments illustrate two general methods.

EXPERIMENT 330 - To prepare a wet pigment for use in a lacquer
Drain off free water on a filter paper and leave the precipitate on the paper until it dries by by evaporation.  Brush it from the filter into the mortar and grind it to a fine powder, adding a few drops of acetone toward the last. It can now be mixed with the lacquer.

EXPERIMENR 331 - Another way to prepare a wet pigment for use in a lacquer
Sometimes the pigment dries to a hard mass which is not easily pulverized.  If so, do not let the precipitate dry by evaporation, but pour over it while on the filter paper some acetone, a few drops at a time, continuing until the acetone solution which has passed through the filter is at least twice the volume of the original precipitate.  The acetone washes the water out and leaves the pigment wet with acetone ready to mix with the lacquer.

EXPERIMENT 332 - Testing white paint for lead
Substitutes are often used for the white lead (basic lead carbonate) used as pigment in paint.  To test whether lead is present in paint, spread a little of the paint on a board with a brush.  Now put five measures of sodium bisulphate in your gas generating flask with about half a test tube of water. Add about three measures of powdered iron sulphide and fit the stopper with the gas delivery tube to the flask.  Warm the contents of the flask to start gas evolution, then hold the board so that the paint is exposed to the hydrogen sulphide gas coming from the delivery tube.  If lead is present, lead sulphide will form and the paint will be blackened.  Paint containing lead compounds should be avoided in laboratories where fumes would darken it.  Even the smoke in cities contains enough hydrogen sulphide to darken lead paint.  Since zinc sulphide is white, zinc pigments are more satisfactory under these conditions.

EXPERIMENT 333 - Testing water color paints for carbonates
Evaporate some of the paint dry in a spoon, heating until the residue is white.  Allow the residue to cool, then add a few drops of tartaric acid solution or vinegar and notice whether the residue gives off bubbles of gas. If it does, the paint contains a carbonate.


How many boys and girls have ever been instructed regarding the applications of chemistry in the home.  In fact, how few of us there are who really realize what an important part chemistry plays in many of the natural processes taking place in the home.  Most of us are inclined to work mechanically, and do this or that according to specific directions, and how seldom do we stop to consider what is taking place chemically in the environment of home surroundings.  A household kitchen is a good example of a practical chemical laboratory.  It is very important today that we all realize the relationship of this household unit to our everyday life, especially simple applications of chemistry when dealing with the necessities of life, such as pure food and water, proper sanitation and clothing.



Trade Name
Baking Soda
Beet sugar
Bleaching powder
Blue vitriol
Bone black
Boracic acid
Carbolic acid
China Clay
Common salt
Corn Sugar
Cream Tartar
Epsom salts
Fruit sugar
Fusel oil
Glauber salts
Grain alcohol
Grape sugar
Chemical Name
potassium aluminum sulphate
formaldehyde-phenol (resin)
sodium bicarbonate
gasoline or petrol
calcium chloro-hypochlorite
copper sulphate
animal charcoal
boric acid
sodium tetraborate
mercurous chloride
pinene hydrochloride
silicon carbide
calcium carbonate
aluminum silicate
sodium chloride
aluminum oxide
potassium hydrogen tartrate
glucose (corn sugar)
magnesium sulphate
40% solution formaldehyde
mixed amyl alcohols
benzine or petrol
natural lead sulphide
sodium sulphate
ethyl alcohol
calcium sulphate
sodium thiosulphate
impure carbon
calcium oxide
Trade Name
Lunar caustic
Marsh gas
Milk sugar
Muriatic acid
Vitriol oil
Paris green
Plaster Paris
Precipitated chalk
Red lead
Rochelle salt
Rock salt
Sal Ammoniac
Slaked lime
Soda (washing)
Soft soap
Soluble glass
Spirits of Hartshorn
Sugar of lead
Sugar of milk
Table salt
Turnbull’s blue
Venetian red
Water glass
White lead
Wood alcohol
Chemical Name
lead monoxide
silver nitrate
cresol soap solution
magnesium oxide
calcium carbonate
hydrochloric acid
potassium nitrate
con. sulphuric acid
copper aceto-arsenite
calcium sulphate
calcium carbonate 
calcium oxide
lead tetraoxide
pot. sodium tartrate 
sodium chloride
benzoic sulphimide
ammonium chloride
potassium nitrate
silicon dioxide
calcium hydroxide
sodium carbonate
potash soap
sodium silicate
ammonia solution
lead acetate
sodium chloride
hy-magnesium latrate
ferrous ferriccyanide
ferric oxide
sodium silicate
basic lead carbonate
calcium carbonate
methyl alcohol



How many boys and girls realize the important part that the family doctor plays in the daily life of a community?  He must always he ready to respond to calls during day or night when he is needed to relieve suffering and human pain.

There is no need greater, no need more urgent than that of the man or woman or the child in illness or in pain; there is no need so great to the individual who is suffering as the need of that moment for one who can soothe or save.  To the sufferer the whole world is in the physician who comes at his call. To that sufferer the physician represents life or life's going. That service for which the patient waits hopefully, painfully or desperately is the sort of service that every physician must have at hand at every hour and every day of the three hundred and sixty-five days of the year.  It may be a stomach ache or it may he the misery and torture of a sudden or chronic illness.  The physician must be ready for whatever it is.  What a welcome friend he is at the bedside in the time of sickness.

It becomes the duty of the physician not only to soothe, relieve or cure, but in order to do that he must instill confidence in his patient and then justify this confidence.  That is no small task for any man or woman.  To accomplish this he must give the very best of all that he has of knowledge, of technical skill and in addition he must give something and sometimes a great deal of himself.  This giving is not of just one hour nor of just one day, but of every hour and every day.  His own business, his own family, his own pleasures, his own leisure must be sacrificed, suspended or dropped in order that he may serve those who need him.


Chemistry has done much to help the family doctor in his work.  Today he is dependent on drugs manufactured and synthesized by chemists for the successful practice of his profession. This relationship of the doctor and the chemist is illustrated in the following table or chart.


Natural Drugs
The chemist has improved on the methods of isolating drugs from plants, thereby providing drugs of greater purity for the physician to use.
Synthetic Drugs
The chemist has duplicated and in many cases has improved upon drugs found in nature.
Drug Adulteration
The chemist has devised methods for detecting drug adulteration, thereby protecting the public from fraud.
Bacteria and Microbes
The chemist has added to our knowledge of the life processes of these lower organisms. The physician has been taught to how to prevent the destructive diseases caused by these lower organisms.
Germicides and Antiseptics
The chemist has pared valuable antiseptics for the use of surgeons which prevent danger from infection after serious operations.

Anesthetics and Saporifics
The chemist has enabled the surgeon and dentist to perform painless operations by providing many new organic combinations possessing anesthetic properties.
Light Radiation
The chemist has cooperated in making effective the application of artificial radiation. As a result the physician is enabled to control the ravages of specific diseases and regulate proper nutrition for growing children.
Radium Extraction
The chemist has worked out practical methods for extraction of radium from ores, thereby providing an effective method of treating cancer
Metallurgy of Iron and Steel
The chemist has provided better instruments to be used by the surgeon in making new alloys of iron and developing improved methods for tempering steel.
X~Ray and Fluoroscope
The chemist has synthesized several new chemicals for X-ray plates and fluoroscope screens.  These enable physicians to make more accurate diagnosis.



Don't touch a wound with your fingers or any instrument.
Don't put an unclean dressing or cloth over a wound.
Don't allow a bleeding to go unchecked.
Don't move a patient unnecessarily.
Don't allow a patient with a fracture or suspected fracture to be moved until splints have been applied.
Don't neglect shock
Don't burn a patient with an unwrapped hot-water bottle or other heated object.
Don't fail to give artificial respiration when needed.
Don't fail to remove false teeth, tobacco, and chewing gum from the mouth of an unconscious person.
Don't permit air to reach a burned surface.
Don't wash wounds.
Don't reduce dislocations, except of the finger and lower jaw.
Don't put a quid of tobacco on a wound
Don't leave a tourniquet on over 20 minutes without loosening.
Don't forget to send immediately for a physician.


Some common drugs and chemicals which are safe to apply externally for local treatment to the skin and wounds in case of minor injuries:


Silver nitrate solution            
Tincture of iodine 
Carbolic acid solution (phenol)        
Potassium carbonate solution
Sodium carbonate solution
Zinc chloride solution
Sodium hydroxide solution

Antiseptics and Disinfectants

Boric acid
Salicyclic acid
Cresol solution
Phenol or carbolic acid solution
Hexylresorcinol in form of ST. 37
Hydrogen peroxide
Potassium permanganate
Chlorinated lime


Tannic acid
Silver nitrate
Bismuth subgallate
Ferric sulphate


Ferric chloride
Alum (ammonium or potassium aluminum sulphate)

Protectives (surface treatment)

Zinc oxide
Talcum powder 
Magnesium carbonate
Bismuth subnitrate



Fixed oils and fats

Local analgesics for pain and itching

Aqueous ammonia  
Carbolic acid solution
Sodium bicarbonate

Emergency Medicines

Ammonia vapor: Inhaled through the nostrils is a stimulant and delays fainting.  Do not breathe strong ammonia vapors.

Tincture of aranica: Useful as a liniment and valuable as a liniment for treatment of sprains and bruises. Almost always found in mother's medicine cabinet.

Bicarbonate of soda: Known as baking soda. Used in treatment of burns.

Camphor: Comes in gum form and also as spirits of camphor. Camphor should not be applied directly to open wounds.

Ginger: Tincture of ginger is useful for bowel complaints. Trust to your mother to properly apply this remedy.

Glycerine: Recommended for burns. Mixed with rose water it makes a practical lotion.

Peppermint: Tincture of peppermint is a well-known home remedy oftentimes used by your mother.

Witch hazel: Extract of the plant witch hazel. A remedy for sprains, contusions, wounds and swellings. Also good for chapped hands, burns, scalds and abrasions.

Vaseline: Recommended for burns and scalds.

Carron oil: For burns and scalds, formula: Mix equal parts lime water and raw linseed oil and shake thoroughly. This forms a creamy emulsion and can be used freely without harm.  Olive oil or cotton seed oil may be substituted for linseed oil.

Limewater: Always available at a drug store for both internal and external use.

Help in Case of Accidents

Burns and scalds: Cover the surface of the wound with bicarbonate of soda and lay over it a wet cloth. Olive oil and linseed oil alone or mixed with limewater are useful.

Snake bite: Suck the blood from the wound and cauterize with a caustic as tincture of iodine, silver nitrate solution or sodium hydroxide.

Dog bite: Treat the same as in the case of snake bites.

Bee stings: Apply diluted ammonia solution, salt water solution, or tincture of iodine.

Fainting:  Lay patient on the back.  Furnish with plenty of fresh air and moisten face with cold water.  Keep head lower than rest of body.


Foreign substance in eye: Pull the upper lid downward away from the eyeball over the lower lid and then release.

Pharmaceutical Preparations

Capsules:  Are made of gelatin oftentimes mixed with a little glycerine. These are used for oils and solutions of drugs in oils. Hard gelatin capsules are used for dispensing powders.

Take a gelatin capsule and apply your test recommended for protein.

Take a gelatin capsule and apply your test recommended for sulphur in protein.

Collodions:  Solutions of pyroxylin (gun cotton) in mixtures of ether and alcohol or acetone.  They are used for external applications.

EXPERIMENT 336 - Preservation of animal matter
Place a piece of beefsteak in a salt mouth bottle and add one spoonful of formaldehyde solution, which can be obtained in any drug store. Cork quickly and seal the bottle with a coating of collodion.

EXPERIMENT 337 - Putrefaction of meat
Repeat the previous experiment, using only meat, and do not seal the bottle with collodion.  Let both bottles stand around at ordinary temperature. Which sample will first show evidence of putrefaction?

Decoctions: These are aqueous preparations made by boiling vegetable substances in water.

EXPERIMENT 338 - Decoction of bayberry leaves
Collect some bayberry leaves, dry them, and prepare a strong decoction. Filter and allow to stand.  Notice the odor of the solution.

EXPERIMENT 339 - Balsam
Repeat the previous experiment, using balsam twigs.

Emulsions:  Are aqueous preparations in which oils or resins are suspended by means of colloidal substances. Fresh milk is an emulsion.

Extracts: Are preparations made by evaporating solutions of the soluble constituents of vegetable or animal matter.

EXPERIMENT 340 - Bayberry extract
Select 50 grams of bayberries and mix with five test tubes full of carbon tetrachloride.  Cool and filter; then let the carbon tetrachloride evaporate and bayberry wax will be left behind. This is an extract of crude bayberry wax.

Infusions:  These are aqueous preparations made by pouring hot water over a vegetable drug.  The best illustration is the preparation of ordinary tea or coffee in a percolator.

Mucilages:  These are aqueous solutions of gums or the mucilagenous principles of many plant substances.


Fixed oils: These are neutral glycerine esters of vegetable and animal fatty acids.  The acids present are generally oleic,  palmitic and stearic acid.

Essential oils: These are oily liquids derived from plants. Oil of wintergreen is an example.

Spirits: These are alcoholic solutions of volatile substances. Alcoholic ammonia is an example of a spirit.

Syrups: Are concentrated solutions of sugars and water. Honey is a natural syrup.

Tinctures: Are alcoholic extractive preparations of vegetable drugs. Tincture of iodine is a specific case of a tincture preparation of an inorganic element.

Ointment: Soft, fatty solids of such a consistency that they may be spread over the skin. They are generally used as simple protectives.

"A bayberry candle burned to socket brings health to the home and wealth to the pocket."

EXPERIMENT 341 - Preparation of bayberry wax
Collect in the Fall of the year about one pound of bayberries and place them in a large bottle. The bottle should be about one~half filled. Then pour over the berries a mixture made up of six parts of gasoline and one part of wood alcohol. Let stand at ordinary temperature and agitate frequently. After standing for two or three days, then drain off the gasoline mixture into a round bottom flask, connect with a Liebig condenser and distil off the solvent at the lowest possible temperature by heating the flask in a steam or hot water bath and condensing the distillate with an efficient condenser. This distillate can be used for further extractions.  After removal of the solvent the dissolved bayberry wax will be left behind as a dark colored oil.  On cooling it will solidify to a greenish colored wax.  If exposed to the air for several hours this wax can be practically freed of all traces of solvent.  The wax can be preserved in the form of moulded cakes of any shape desired if you have the proper mould.
EXPERIMENT 342 - Making a bayberry candle
Select a piece of glass tubing of proper diameter and length for moulding a candle.  Insert in one end of the tube a cork through which is drawn a string to serve as a wick.  Hold the wick string taut, fill the tube with melted wax, and let cool.  After complete solidification then remove the cork and gently warm the tube. The candle will easily slip from the tube after heating.

EXPERIMENT 343 - Balsam pillows
The balsam tree is well known for its fragrant aroma. Secure some green boughs of a balsam tree and chop the twigs into small pieces. Balsam twigs in this form are very fragrant and are an excellent material for filling pillows at Christmas time. 

EXPERIMENT 344 - Making a partridgeberry bowl
If you are a wild flower lover and are interested in making a unique home decoration at Christmas time, construct a partridgeberry bowl. The leaf of the partridgeberry is evergreen and the berries a brilliant red. Select a round, glass bowl about four inches in diameter, fitted with a tight glass or metal cover. Select uniform sprays of the plant and arrange in the bowl so that both leaves and berries are visible. 


If properly  packed the sprays will continue to grow. The partridgeberry bowl requires no attention except a few drops of water once a month. Keep tightly covered to conserve water.
EXPERIMENT 345 - Evergreen trees
Every boy and girl should be familiar with our native evergreen trees. Collect sprays of the following: Arbor vitae, American yew, balsam, fir, hemlock, juniper, red cedar, white spruce, American arbor vitae, white pine, red spruce and Norway spruce.  Compare the foliage of these species and note any characteristic differences.  Which species are commonly used for Christmas trees?

EXPERIMENT  346 - Around the fireplace at Christmas
The fireplace is the center of family life at Christmas time, as well as in the long winter evenings.  What can you suggest in the way of a Christmas decoration to make it more attractive?  Make the proper selection of evergreen, etc., for roping, sprays and provide balsam needles and selected cones for burning in the fireplace.


Material for preparing interesting Christmas gifts for our friends can easily be made by chemically treating wood and other combustible material which when thrown on burning fires will produce colored flames. Small pieces of well dried wood, pine cones, corn cobs, charcoal, knots and rolls of old newspapers are all suitable materials for use in making colored fires.


To apply the chemicals, take a small wooden pail, a tub or an old earthen crock.  Do not use a metal container because the chemicals will destroy the metal.  Dissolve the chemical to be used in the proportion of one pound to a gallon of water. In some cases ot will not be necessary to use so strong a solution.  After the chemical solution is ready, then take your material to be soaked (pieces of wood or cones) and suspend them in a porous bag, a wire basket or some similar container, and dip them into the chemical solution.  Let them soak for two or three hours so that the solution will completely penetrate the combustible material. Then remove from the solution and allow to drain, finally spreading on paper for complete drying.  CAUTION!  When preparing the chemical solutions and also when soaking wood and cones do not put your hands in the solutions as they are corrosive and will injure the skin.

EXPERIMENT 347 - A blue fireplace flame
Use blue vitriol or copper sulphate as your chemical and dissolve as directed in water.  This chemical is not expensive and can be purchased at a wholesale drug house.  Wood shavings, cones, coarse charcoal, and dried branches of evergreen trees
make suitable material for soaking.

EXPERIMENT 348 - A purple fireplace flame
Potassium permanganate is a practical reagent for cone or wood soaking. A beautiful purple color characteristic of potassium will be produced.

EXPERIMENT 349 - A green fireplace flame
For producing this color use a solution of boric acid.


EXPERIMENT 350 - A red fireplace flame
Two chemicals can be utilized for producing a red flame: lithium chloride or strontium nitrate. It will not be necessary to use more than one-quarter to one-half of the quantities of chemicals recommended in the general directions. The red colors are more intense and therefore less chemicals are required to produce the desired results.

EXPERIMENT 351 - An orange fireplace flame
For producing an orange fire, calcium chloride is recommended.  This is a very cheap salt.

EXPERIMENT 352 - Christmas souvenirs
Prepare small bags of netting and then place some dried wood shavings or small cones in each of them and tie with bright red ribbons or cord. These bags make excellent gifts at Christmas time and give much pleasure when burned in fireplaces or open hearth tires.

EXPERIMENT 353 - A Merry Christmas greeting
Make a strong water solution of potassium nitrate.  Using this solution as an invisible ink, write on a sheet of white paper the following: "Merry Xmas."   Make the lines heavy and writing continuous without any breaks.  Allow the paper to then touch the beginning of the writing at the letter 'M ' with a red hot wire.  A spark will develop and run over the paper tracing out the words "Merry Xmas.”   This is an example of fire writing.

EXPERIMENT 354 - Happy New Year
Repeat the above experiment using the greeting "Happy New Year."  Make writing continuous.

EXPERIMENT 355 - April Fool
Repeat the above experiment, using the words "April Fool.”

EXPERIMENT 356-Believe it or not
Repeat the above experiment using the well-known Ripley remark "Believe It or Not."


While there is quite a variety of foods and the compounds present in foods are very numerous and often very complex, yet they may al be included in a few a general classes.  The edible portion of our foods consists essentially of proteins, fats, carbohydrates, mineral matter and water.

Proteins, which occur to a larger extent in animal foods, serve to replace the worn-out tissues of our bodies and to supply material for growth. The carbohydrates and fats are both oxidized in the body to carbon dioxide and water and consequently  serve as a source of heat and muscular energy. If carbohydrates or fats are lacking in the foods we eat, the protein material in them furnish the necessary heat and energy.  The mineral matter supplies the necessary material for bulding up the solid tissues of the body besides taking other complex parts.

Proteins occur in both animal and vegetable foods and are composed of the elements carbon, hydrogen, oxygen, nitrogen and small amounts of sulphur and phosphorus. Carbohydrates are chiefly found in vegetable foods in the form of starch and sugars and are composed of the elements, carbon, hydrogen and oxygen.  Fats occur in both classes of foods, but occur in much larger quantities in animal foods.  They are


compounds of glycerine with organic acids and are composed of the elements carbon, hydrogen and oxygen.

It is important, since the various constituents of our foods serve different purposes, that we use the proper proportion of these materials in order to keep up a healthy body.  For example, during the winter months we should eat a larger amount of animal foods since they contain a larger proportion of fats necessary to keep the body warm.  During the warm weather we should eat less meats or animal foods and more vegetables or fruits. They contain carbohydrates which serve to keep up the necessary body heat and energy.  How often people are made very uncomfortable and sometimes sick by their ignorance of the amounts and kinds of foods that the body requires during the different periods of the year. Did you ever realize that sometimes a heavy cold is brought about by over-eating. This happens quite often when we are not exercising the body enough; the foods are not oxidized or burned up, the blood becomes stagnant and we are sick. The body is a very intricate form of machinery, each part performing its own particular function the same as the different parts of a watch.  If we abuse any one of these parts by eating too much with an insufficient amount of exercise or by not eating the right kinds of foods, something goes wrong and we are sick.

Throughout the country there are chemical laboratories which are conducted by the Government and local public health boards for the purpose of analyzing and testing foods as to their purity.  A few years ago the Government enacted the Pure Food Law, which requires that foods which are bought by the public should be free of impurities or adulterants as they are called. Adulterants are materials sometimes mixed with foods to make them cheap. For example, oleomargarine was quite often used to take the place of good butter, whereas, it was a very poor substitute. In other foods harmful chemicals were often used to preserve them. Quite often foods were adulterated to give them weight, bulk or proper color. For example coffee was often weighted with chicory.  Today, things  are quite different; most of the foods on the market are pure or nearly so.

The square meal today has come to have six sides, all of which are necessary for human beings, if they wish to enjoy good health. First, water is the most important of these sides.  Proteins: bones require proteins and minerals. If human beings do not get a proper amount of proteins and mineral substances, for bone growth, they suffer from rickets and other bone disorders.  Calcium and phosphorus are the two chief mineral elements needed for bone growth. It is very important to realize the importance of calcium as one of the essential elements in the metabolism of human beings. In the growth and repair of the bony frame-work and teeth of the body it is very necessary.  Calcium plays a very distinct role in the tuberculosis patients' bid for the return of good health.  A careful study of all available data indicates that about 95% of school children suffer from tooth decay.  The prevention of tooth decay would be an untold boon to the public.  A lack of vitamin C in the diet leads to an increase in tooth decay.  The lack of this vitamin produces a degeneration and retards the nutrition of the teeth.  Vitamin D is a potent substance and also a regulator of tooth decay.  Blood serum high in phosphorus is essential to tooth immunity. The chief fuels used by the body are known as carbohydrates.  Two forms of carbohydrates which man uses in food are starches and sugars. Foods rich in these substances are important energy-giving foods.  Fats: These are important constituents of such foods as butter, cream, bacon.  Fats serve two purposes in the body: They serve to keep the body wanrm by supplying a padding around the muscles; they also serve as a reserve fuel supply, and are drawn upon by the body as a source of energy. Materials which regulate body processes:  common salt, iron, mineral substances, and the naturally occurring principles known as vitammins.



EXPERIMENT 357 - The use and care of aluminum ware 
Obtain an old aluminum pan and put some vinegar in it.  Warm slightly and notice the corrosive action which the vinegar has on aluminum. Add a small quantity of salt to the vinegar and notice that the corrosive action is increased. Put a small quantity of lye in the aluminum pan, dissolve it in water, and notice that this also corrodes the aluminum.

This experiment shows that acids and alkalies should not be put in aluminum ware for cleaning or polishing. Neither should acid foods be prepare or kept in aluminum vessels. Salad dressing containing vinegar and salt, for example, would corrode aluminum pans very badly and also introduce aluminum compounds into the food.

EXPERIMENT 358 - Why zinc vessels are not used for foods
Test the solubility of zinc in acids, for example, warm vinegar. Also test the solubility of zinc in a strong lye solution. You will see that zinc is attacked by acids and alkalies; therefore, foods should not be kept or prepared in zinc vessels. Sodium chloride solution also attacks zinc readily, and as the soluble compounds of zinc are poisonous, it would be very dangerous to use zinc vessels in preparing foods.

EXPERIMENT 359 - Cooking in copper vessels
Test a strip of copper in acids; for example, two measures of sodium bisulphate in a test tube one-quarter full of water, strong vinegar, etc.  Notice that especially when the solution is heated the copper dissolves in the acids. Add a few drops of household ammonia to an acid solution which has acted on copper. We find, therefore, that copper vessels are not good for cooking foods as the copper will dissolve in acids and the soluble salts of copper are poisonous.

EXPERIMENT 360 - Testing silver plate 
To find out whether an article is plated with nickel or with silver prepare a solution of four measures of sodium bisulphate in a test tube half full of water.  Put the article which you wish to test in this solution and warm it for a few minutes.  If a greenish solution is formed, the article contains nickel.  Test the solution by adding sodium carbonate until it no longer effervesces and then generate hydrogen sulphide gas, and pass the gas through your delivery tube into the solution. A black precipitate indicates nickel.

EXPERIMENT 361 - Cleaning silverware
Sodium thiosulphate dissolves silver sulphide. Prepare a solution of two measures of this salt in a test tube three-quarters full of water. Moisten a soft cloth in this solution and rub a piece of silverware, which is tarnished with silver sulphide.

EXPERIMENT 362 - Removing iodine stains
The blue color formed with iodine and starch or the brown iodine stains can be removed from flesh or from fabrics by means of sodium thiosulphate solution.

EXPERIMENT 363 - A test for soil in the flower pot
Remove a sample of soil from your mother’s flower pot and mix with sufficient clear water to make a thin paste. Insert a strip of blue litmus paper in the mixture and allow it to remain for half an hour.  Withdraw the paper and wash with water.  If the paper has turned pink the soil is acid.


EXPERIMENT  364 - A fragrant paste wax
Carnauba wax and one part of bayberry wax are mixed with sufficient turpentine to form a thick paste. Be sure to mix thoroughly in order to obtain a uniform paste.  Apply this mixture to a piece of furniture that your mother would like renovated.  Rub briskly when dry to obtain a good polish.

EXPERIMENT 365 - Keeping the surface of window panes clear
In cold weather one often desires to keep a window pane in the kitchen free from ice in order to see out of doors. Also, when driving a car in rain, snow, sleet, fog or frost, it is difficult to keep the windshield so that you can see through it.  A very simple compound can be made of soap and glycerine which will prevent the window panes from becoming fogged or streaked with rain or ice.  The same compound can also be used on eye glasses to keep them clear in bad weather.

Shave some white soap by scraping with a knife and put 25 measures of the soap shavings and four or live drops of glycerine in a glass or cup.  Add a few drops of water and stir thoroughly with a stirring rod until a smooth stiff paste is formed. Keep this paste in a tight container and when needed take a little on your fingers and rub over the outside surface of the glass to be kept clear.

EXPERIMENT 366 - Colored soap
Put a heaping spoonful of shaved soap in a mortar or cup and add two or three drops of cochineal solution.  Grind the mixture thoroughly and when the whole mass is a uniform color, work it up into a cake with your fingers. By using different dyestuffs, almost any desired color of soap can be made.

EXPERIMENT 367 - Perfumed soap
Put a heaping spoonful of soap shavings into your mortar and add four or five drops of a selected perfume.  Grind the mixture up thoroughly and then form it into a cake by pressing it into a smooth mould.  Various perfumes can be used to make soap any odor desired.

EXPERIMENT 368 - Liquid soap
Put a spoonful of soap shavings into your mortar and add water, a few drops at a time, stirring the mixture continually with the pestle.   When the proper consistency has been reached pour the liquid soap into a bottle if you wish to keep it.

EXPERIMENT 369 - Transparent soap
Take a piece of Ivory soap about the size of a marble and put it in the bowl of a spoon together with four or five drops of glycerine.  Now heat the spoon over the flame for a few minutes until the soap has meltedy and mixed with the glycerine. Upon cooling you will find that the mass is now transparent.  Transparent soaps are also made by mixing alcohol or sugar with ordinary soaps.

EXPERIMENT 370 - How soap cleanses
Have you ever thought why it is that soap will immediately remove dirt from your hands; while if you try to wash them without soap it takes very much harder rubbing?  Soap cleanses by emulsifying or holding the dirt in suspension and then by rinsing the soap away with water, the dirt goes away with it.  On the other hand, if you wash with water which does not contain soap, the water will loosen the dirt, but in order to remove the dirt it must be rubbed away. Try this experiment.

Obtain a small amount of grease or oil and fill a test tube about one-quarter full with it.  Now add water until the tube is half full and shake the tube for a few minutes until the oil and water are thoroughly mixed. When you stop shaking, the oil and water


separate very rapidly. Now add a small amount of soap solution to the oil and water in the test tube and shake again.  This time the oil and water stay mixed together for some time before they separate, and it would be an easy matter to remove the oil while it is held by the soap and water.

EXPERIMENT 371 - Laundry soap
Put three or four measures of soap shavings in the mortar and grind it to a paste with four or five drops of water glass. When yu have a good mixture scrape it in a pile on a plate or tin pan and let it dry.  Laundry soap frequently contains water glass or sodium silicate as well as sodium carbonate.

EXPERIMENT 372 - Borax soap
Soap is sometimes mixed with borax and used as laundry soap, etc.  Grind together in your mortar five or six measures of soap shavings with two measures of Borax and three or four drops of water.  Scrape the paste from the mortar on to a tin pan after it has been thoroughly mixed and then let it dry.

EXPERIMENT 373 - Medicated soap
These soaps are mixed with various antiseptic substances, such as carbolic acid, etc.  When used a small amount of the antiseptic substances dissolves and comes in contact with the surface to which the soap is applied.  You can make a small quantity of medicated soap by mixing a little soap and acid with some water and grinding the mass in the mortar until it is well mixed and then drying the paste.

EXPERIMENT 374 - Dissolving grease
Try to dissolve a small piece of lard, or butter, or grease in water. If the water is heated the grease may melt and become distributed through the water, but on standing it will again come into a mass and will not dissolve. 

Now put a small piece of grease in a test tube with a few drops of carbon tetrachloride and notice that it dissolves almost immediately. Try to mix carbon tetrachloride with water.  Mix some carbon tetrachloride with water containing suspended fat.  What becomes of the fat?

EXPERIMENT 375 - How biscuits are raised
Put a teaspoonful of flour in a tumbler and add four measures of sodium bicarbonate.  Stir this mixture with a little water until you have a dough like bread dough.  Now put a piece of this dough about the size of a marble on your spoon and heat it over the alcohol lamp flame. Notice that the dough swells and that it becomes porous or light, due to the gas that is formed in it.

Ordinary baking soda is sodium bicarbonate; when treated it gives off part of the carbon dioxide gas which it contains, so when used in biscuits, cakes, etc., the gas coming off raises the dough and makes it porous. In cooking, sour milk, or other acid, is used with the baking soda. This neutralizes the soda and gives off more carbon dioxide gas.


EXPERIMENT 376 - Protein in the white of an egg
Place in a test tube some white of a boiled egg and mix well with one measure of pulverized calcium oxide. Then add three or four drops of water and heat the mixture.


over your alcohol lamp and smell the gas that is generated.  Conduct some of the gas evolved over a moistened red litmus paper. Proteins contain nitrogen.  Egg white is a protein substance and on heating with calcium oxide is decomposed with liberation of ammonia. 

Apply the preceding experiment, using a chicken's liver.

Apply the test again, using a lamb's kidney.

Repeat experiment 376 using a piece of dry cheese.

Repeat experiment 376 using the skin of a potato.

Repeat experiment 376 using a sample of your mother’s breakfast cereal.

Repeat experiment 376 using a sample of your mother's favorite glue.

Repeat experiment 376 using a piece of rayon silk.

EXPERIMENT 384-Sulphur in proteins
Put a half spoonful of the white of an egg into a test tube and add one measure of copper sulphate and two measures of calcium oxide. Heat the test tube over a flame and allow the mixture to boil for two or three minutes. Notice the black precipitate of copper sulphide which is formed, showing that proteins contain sulphur.

Repeat experiment 384 using a piece of the finger of an old leather glove.

Repeat experiment 384 using a piece of dried cheese.

Repeat experiment 384 using a piece of rubber tubing.

Repeat experiment 384 using a piece of woolen yarn. Also test the piece of woolen yarn for protein.

Repeat experiment 384 using ground mustard seed.

EXPERIMENT 390 - Testing canned goods for copper
This test may be applied on a great variety of food articles such as canned peas, beans, ordinary spinach, apricots, pears, pickles, saurkraut, etc.  Grind together a selected sample of the food to be tested with two or three measures of sodium bisulphate and several spoonfuls of water.  Heat this mixture for several minutes below the boiling temperatire of water (212° F.) in a sauce pan and finally let stand on the back of a warm stove.  Finally drop into this hot solution a polished  wire nail and let


it remain there for about one-half to one hour. It is well to stir the contents of the pan occasionally. If the wire nail takes on a red color due to copper plating this will be evidence that the sample of food product you have tested will contain traces of copper.

EXPERIMENT 391 - Copper in oysters
Repeat experiment 390 using the pulp of an oyster.

EXPERIMENT 392 - Copper in scallops
Repeat experiment 390 using the meat of a scallop.

EXPERIMENT 393 - Copper in a round clam
Repeat experiment 390 using the meat of a round clam.

Sea food is frequently contaminated with traces of copper This is carried oftentimes to the sea water by sewage drainage, especially in areas where certain industrial operations are carried on extensively. Oysters are often found contaminated with copper.

EXPERIMENT 394 - Testing coffee
Coffee does not contain starch. It is often contaminated, however, with starchy materials. Some of these are ground beans, peas and chicory. The microscope will serve many times to detect such adulterations. A test for starch may be used, therefore, to show the presence of these adulterants. Digest the coffee with hot water to make a strong solution. Treat with a spoonful of absorbent charcoal to remove the color, and finally dilute with a little water to obtain a light colored solution.  Then apply your starch-iodine reaction to test for starch. A blue coloration will be formed if starch is present.

EXPERIMENT 395 - Decolorizing hamburger steak 
Meat turns a deep red color on long exposure to the air. This is due to changes in the blood content. To bleach out meat put a small quantity of chopped meat in a test tube and add some hydrogen peroxide solution.  Warm the solution gently and let stand. The chopped meat will be bleached and lose all its color.

EXPERIMENT 396 - Hydrogen peroxide and liver
Grind a piece of chicken liver and suspend in some hydrogen peroxide solution.  Note the change in the appearance of the liver.

EXPERIMENT 397 - Hydrogen peroxide and a lamb’s kidney
Grind a piece of lamb's kidney and suspend in some hydrogen peroxide solution.  Note the change in appearance of the kidney. Hydrogen peroxide is an excellent preservative for animal matter and will prevent such materi from putrefynng.

EXPERIMENT 398 - Chicken feathers
Test chicken feathers for both protein and sulphur.  The feather should be cut into fine pieces before applying the fusion test with calcium oxide. Burn some and note the odor produced.

EXPERIMENT 399 - Honey comb
Secure some natural honey comb from a hive and cut out a small piece and clean it thoroughly. Then apply to this material the regular procedure, as described above for testing for protein and sulphur, by fusing with calcium oxide.


EXPERIMENT 400 - Iron in honey comb
Incineratea piece of honey comb in a porcelain crucible, and test the residue or ash for iron.

EXPERIMENT 401 - Bees' wax
Test some refined bees’ wax for protein, iron and sulphur. Determine what happens when a small piece of bees’ wax is warmed in a test tube with some (a) turpentine, (b) carbon tetrachloride, (c) benzol, and (d) denatured alcohol.

EXPERIMENT 402 - A wasp's nest
Detach from the roof of your mother's attic an old wasp's nest.  Incinerate this and examine the ash for silica and iron.

EXPERIMENT 403 - Composition of a' wasp's nest
Apply a regular test for protein and sulphur.  A wasp's nest is a combination of cellulose similar to artificial paper.

EXPERIMENT 404 - House flies
Kill 12 or 15 large house flies and incinerate in a crucible. Test the ash of the flies for iron.

EXPERIMENT 405 - The house wasp
Kill two or three large house wasps and grind them to a pulp in one-third test tube of water.  After thorough digestion then filter and test the water extract with blue litmus solution.  The color will be turned to red due to the presence of formic acid.  The wasp excretes formic acid in its sting.

EXPERIMENT 406 - Tannin in tea
Make a very strong water solution of hot tea.  Cool and pour off the clear liquid and add about one measure of ferric ammonium sulphate.  Shake well.  On standing a black color will develop due to the formation of iron tannate.

EXPERIMENT 407 - Sanka coffee
Repeat experiment 406 using some strong Sanka coffee solution.

EXPERIMENT 408 - Potato sprouts
Secure some clean colorless common potato sprouts and make the following tests (a) incinerate and test for iron; (b) test for protein; (c) test for sulphur; (d) test for starch.


EXPERIMENT 409 - Making a low temperature bath
Follow the technique of the ice cream manufacturer and mix some crushed ice with pulverized salt.  Read the temperature with your thermometer.

EXPERIMENT 410 - A sugar bath
Repeat the preceding experiment, using some household granulated sugar in place of pulverized salt.  Do the sugar and salt produce the same results?  Explain.

EXPERIMENT 411 - Iron in your tonic
Pour one-quarter of a test tube of your spring tonic mixture into a test tube and add to it one-third a test tube of sodium ferrocyanide solution.  The production of a blue color will prove that iron is present.


EXPERIMENT 412 - Iron in blood
Repeat experiment 411, using a few drops of animal blood. Mix with water and then add the sodium ferrocyanide solution.

EXPERIMENT 413 - Decolorizing tincture of iodine
To a little tincture of iodine add a solution of sodium thiosulphate (hypo solution).  Shake well and observe that the iodine color is lost. This reagent is useful for removing iodine stains from clothing. Try the experiment using a corner of your handkerchief.

EXPERIMENT 414 - Stains on your fingers
Fingers stained with juices of fruits may be cleaned by washing with sulphur dioxide water.

EXPERIMENT 415 - Cleaning a straw hat
Mix two measures of sodium bisulphite with one measure of tartaric acid and one measure of borax. Dissolve the three reagents in hot water and scrub your straw hat with the solution. After thorough rubbing with a brush then wash with pure water and dry the hat in the sunlight.

EXPERIMENT 416 - Removing paint from cloth
Lay a pad of blotting paper on the side of the fabric which has a paint spot on it.  Then rub the other side of the fabric with a piece of flannel moistened with carbon tetrachloride. This chemical will dissolve paint and carry it into the blotting paper.  The success of this method depends on the use of some absorbent material to take up the organic solvent when it dissolves the paint.

EXPERIMENT 417 - Preparation of a good glue for labels
Dissolve one teaspoonful of gum arabic in two and one-half test tubes of water by warming. Then add four teaspoons of common sugar and one teaspoon of starch and finally boil the solution for a few minutes. lf the gum solution is too thick,  on cooling, add more water.  If you wish to preserve the gum from fermentation and action of mould, add about one teaspoon of boric acid. Hydrogen peroxide solution may also be used to keep it sweet.

EXPERIMENT 418 - Rubber cement
Piace one ounce of latex rubber in a salt mouth bottle and pour over it some carbon tetrachloride.  Cork and let stand until the rubber latex dissolves completely.  Use as needed.

EXPERIMENT 419 - Cleaning marble
Use a mixture of one part of pumice stone, two parts of sodium carbonate, and one part of powdered chalk.  Mix well and rub with a little water.  Then use the mixture for rubbing the marble surface.  Wash well with water after the treatment.

EXPERIMENT 420 - Vegetable stains on the hands
Rub with a fresh cut slice of raw potato.

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