5. NEW MARVELS OF CHEMISTRY IN EVERY

DAY LIFE

MARSTON T. BOGERT

This selection is made up of parts which fit together like the parts of a hand.

In this diagram the palm of the hand represents a general statement or truth, and the fingers represent illustrations, or proofs, of the general statement or truth. What would you put in the palm as the general statement or truth in this selection, and what would you place on

the fingers as illustrations or proofs of the general statement or truth?

Practically everything we eat, taste, wear, smell, and see has resulted in some way from the ingenuity of chemists. The story of chemistry is like an endless chain it might begin anywhere, and need never end.

Just now you were looking out of the window. That glass is a product of chemistry. Glass is made of soda, lime, and sand. A mixture of these substances is melted down to a bright-red heat. A big molten ball of it is then gathered on the end of a blowpipe. Air is forced through the pipe, and the ball becomes a bulb, the bulb becomes a long cylinder. At the right temperature the cylinder is laid on a table and slit. The cylinder flattens out. That is window glass.

In the hall door of your home or in your office there is a pane of plate-glass. This is made by casting the molten glass. It is first pressed as smooth as possible, then ground still smoother, then polished. It is a product of recent years, chiefly due to American ingenuity.

The desk at which you work was made with steel tools. The steel of which these tools were made is a chemical composition. And these wood-cutting tools had first to be made with other tools that could cut steel.

Once this process was very slow and expensive. The steel tool used in cutting out other tools would get red-hot and lose its "temper," so that it could not cut. Then the worker would lose his temper, too! For he had to stop, resharpen his tools, and waste a great deal of time. Chemists added certain rare metals to the iron that makes ordinary steel, and as a result we have "high-speed steel."

High-speed steel is so expensive that tools are tipped with only a fraction of an inch of it, in much the same way that our finest gold pens are tipped with iridium, to keep them from wearing out. This steel tip is many times as efficient as ordinary steel. Without high-speed steel we could not have cheap typewriters, farm implements, and automobiles; for this product has revolutionized the whole metal industry.

In your medicine-chest, there probably is a little tube containing a substance which is antiseptic, and which solidifies when exposed to air. If you cut your finger or tear away a hang-nail, you apply a little of this substance, and it forms a skinlike covering. That substance is collodion.

Now somewhere near your tube of collodion you may have something made of celluloid, perhaps an eyeshade or a paper cutter. In warm weather especially, you must have noticed that anything made of celluloid smells a good deal like something else you keep handy - camphor. That will not seem strange when I tell you how we came to have celluloid.

In 1863 a boy named John Wesley Hyatt was working as a printer in Albany, New York. He saw an advertisement offering ten thousand dollars for a substitute for ivory billiard balls, and he began to experiment with the hope of getting this reward.

One day, when his fingers were raw from handling type, he went to a cupboard for some collodion to heal his hurts. The bottle containing the collodion had tipped over, and the contents had run out and solidified. When young Hyatt pulled away a little of the stuff from the shelf, he was struck by the fact that it was tough and elastic, and that gave him

an idea. He began experiments, trying to make billiard balls out of collodion.

Presently he heard that some Englishmen had been trying to make camphor and collodion unite to form a solid. The Englishmen had not succeeded, because they had attempted to get the two substances to unite by adding various other substances to them. But Hyatt simply put a mixture of collodion and camphor into a hot press, and out of the press came a semitransparent solid, which he called celluloid. It was hard, light, tough, and could be dyed any color, polished, heated, pressed, stamped, molded, or blown into various shapes.

Innumerable things are made of celluloid: cards and card cases, cuff and collar buttons, cups, drawer knobs, chessmen, piano keys, penholders, spectacle frames, political campaign buttons, hairpins, mirror backs, toy animals, and so on. Young Hyatt's accident with collodion has proved to be the basis of industries worth millions of dollars a year.

Your camera film is made of it. Purses, belts, and leather cushions are often covered with it. Many leather substitutes are made of collodion on canvas.

Years ago the wearing of purple indicated royal birth, for the purple dye was so expensive that none but those "born to the purple" could own it. To-day you can consider anything dyed with purple as a symbol of the marvelous development in our chemical industries.

The original Tyrian or imperial purple of ancient times was secreted by a small sea-snail, found on the eastern coast of the Mediterranean. Behind the head of this snail is a small sac which contains a single drop of a whitish liquid, which when exposed to the air and sunlight becomes first green, then blue, then purple. To get an ounce of the dye the ancients had to extract the liquid from the sacs of at least twelve thousand snails. That is why it cost so much to wear imperial purple.

Modern chemists have learned the chemical constituents

of this purple dye, and now we can make it in any quantity desired by combining certain chemicals in the proper proportion. We get the necessary chemicals from coal, and from our brine wells in Michigan.

Coal is the most wonderful substance on earth. We not only get from it the "royal purple" dye, but tens of thousands of other dyes, though only about one thousand of these are in common use.

When you have an aching tooth to be filled, or one that has to be pulled, the dentist fills a hypodermic needle with a certain drug, and this he injects before and behind the tooth so that the nerves are deadened. Then he can fill the tooth, or even pull it, painlessly. That drug is known as novocaine, and we get it from coal.

Once the argosies and caravans set out to bring from afar the most costly perfumes, drugs, and spices. To-day we get them from coal. It is from coal that chemists obtain the worst smells and the loveliest perfumes, the most fatal poisons and the most beneficent drugs, the finest flavors, the blackest pitch, the most powerful explosives, and the most brilliant dyes.

When a lump of coal is burned in an open grate, the volatile gases escape up the chimney, and we have the phenomena of heat and light. There remains in the grate only the ash or mineral substance. We have lost the most valuable products.

Now suppose you buy a common clay pipe. In the bowl of the pipe put a small lump of soft coal. Stop up the top of the bowl with clay, and hold the bowl over an ordinary gas jet. Presently, if you hold a lighted match near the opening of the pipe stem, you will see a jet of yellow flame. The gases are burning off.

When all the volatile products have been disposed of, take the clay off the top of the bowl and you will find in the bowl a piece of ordinary coke. Now break the stem of the pipe somewhere near the middle, and you will find de

posited there some blackish drops of water containing a sticky substance. This substance is coal tar, the marvel of chemistry.

We extract coal tar from coal in much the same way I have illustrated, and we get four principal products: gas for light, heat, and power; ammonia water (by distilling the gases through water); coal tar and coke.

From the coal tar we can extract a dozen primary products, and from these we can literally build up hundreds of thousands of new substances. One of the most important of these products is carbolic oil, from which we get carbolic acid - a powerful antiseptic. If we treat the carbolic acid with dilute nitric acid, we find that the original carbolic acid has changed into two new substances. One of these is the source of dyestuffs and photographic developers.

There is practically no end to the substances we can get from coal. We are getting now from each of the crude substances contained in coal tar many hundred times as many products as I have mentioned in connection with carbolic acid. But we shall get many more. What we know about coal to-day is comparable to what we know about a book when we have read only the preface.

CLASS ACTIVITIES

1. Name the most important "New Marvels of Chemistry" described by Bogert.

2. Practically everything we eat, taste, wear, smell, and see has resulted in some way from the ingenuity of chemists. Give ex

amples not mentioned in the selection which support this statement.

3. In answering No. 2, were you illustrating Emerson's words: ""Tis the good reader makes the good book"? Explain.

4. Bring to class articles made of celluloid, or any other articles which illustrate the marvels of modern chemistry. Tell of what the other articles are made.

5. Tell some boy volunteer to perform before the class the experiment with the clay pipe and the piece of coal.