Page:Popular Science Monthly Volume 90.djvu/896

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��Popular Science Monthly

��form a solid, transparent, amber-like sub- stance, odorless, heat-resisting, a non-con- ductor of electricity, impervious to most acids, oils and steam, and insoluble in all known solvents.

This substance is used for insulating, es- pecially in automobile ignition work, since it does not burn or soften when heated. It also makes beautiful parasol handles, fountain pens, buttons and numerous other useful articles. The chemical name for this jack-of-all- trades is oxy-benzyl-methylen- ^lycol-anhy- d ri te.

Anothersub- stance which traces)its origin back to the shininglumpof coal is ammo- nia, important in chemical manufacture, in refrigera- tion, as a source of nitric acid and in fertil- izers. Inks of all sorts are de- rived indirectly from coal tar. Among them are printing inks, ranging from cheap newspaper black, made from lamp- black, to thick heavy paste used in CO pperplate printing. Col- ored printing and writing fluids as well

as typewriter ribbons and copying inks are also made.

Vanillin, which has the flavor of the vanilla bean, is obtained from benzene. Creosote is used as a wood preservative and medicine. Benzaldehyde is the base of many exquisite perfumes. Benzoic acid is used as a food preservative and sac- charin is a substitute for sugar, used by diabetic patients. Phenacetine is a drug used in controlling fever, and salicylic acid becomes asperin, used for all sorts of aches and pains.

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���Dr. Ludwig Oulmann, the New York skin specialist, treating a case of baldness with ultra-violet radiations. The lamp used may be regarded as a very intense miniature sun. Twenty minutes' exposure sets up a stimulating action which induces the hair to grow

��Artificial Sunlight for Bald Heads

''HAT causes sunburn? Not the heat of the sun, but the light alone. It is not the light that you can see but the light that you cannot see — what the physicist calls ultra-violet radiation. Just as there are sounds that we cannot hear, so there is light that we cannot see. If our eyes were only differently constituted we might see ultra-violet radiations.

These ultra-violet radiations have very

remarkable curative prop- erties. They kill germs, and they penetrate the skin suffi- ciently to set up a wonder- fully stimulat- ing action. Hence, special lamps have been con- structed which radiate ultra- violet light and which are used for the treat- ment of skin diseases in par- ticular.

Since bald- ness is a skin disease, it fol- lows that phy- sicians have been treating it with ultra-vio- let radiations. The results are often astonish- ing. Many a head as free from hair as an egg has been exposed for twenty minutes, at intervals of three weeks, with the result that in about two months down begins to sprout. There are cases enough to show that ultra-violet radiations restore prema- turely gray hair to its natural color,

A bald head exposed to ultra-violet radiations appears in twenty-four to forty- eight hours as if it has been sunburned. In reality, it has — by an artificial sun of great intensity. The skin peels and tans. Nature is encouraged, as it were, to remove the dead matter and to create new hair.

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