The Romance of Modern Chemistry

CONTENTS CHAPTER XXI FATS AND OILS PAGE The varied sources of fats and oils—Edible fats—Margarine— Drying oils in paints and varnishes—Putty and linoleum— Oils as lubricants and illuminants—Tallow dips and snuffers —Stearine and paraffin wax in candles—Hard and soft soap —Glycerine........................................237 CHAPTER XXII HOW MAN COMPETES WITH NATURE Destructive and constructive work in chemistry—Analysis and synthesis—A red-letter day in 1828—Wohler’s synthesis of urea—How organic, substances are built up from inorganic materials—How artificial alizarin has ousted the natural dye from the market — Natural indigo badly hit — Synthetic versus natural camphor—Artificial rubies .... 248 CHAPTER XXIII THE ADULTERATION OF FOOD Adulteration no new thing—Common foods not always what they seem—Butter and milk—The microscope in the detec- tion of adulteration—Preservatives in food—Boric acid, formaldehyde, salt, and sugar — Strange composition of egg substitute ...................................260 CHAPTER XXIV THE VALUE OF THE BY-PRODUCT Rubbish heaps of our modern civilisation—Blast-furnace slag— Cement and slag wool—A fertiliser as the by-product of steel manufacture—The wonderful story of the soda industry —How refuse has been converted into riches—Alkali waste recovery—Where private profit and public interest have been served together—Old methods threatened by new discoveries 269 CHAPTER XXV VALUABLE SUBSTANCES FROM UNLIKELY SOURCES The unlovely products of the gas-works, and what is got out of them—Undesirable impurities converted into useful materials —Sulphur and sulphate of ammonia—Coal tar—Mr. Mackin- tosh and waterproof material—Wood pickling—Foundation of the aniline dye industry—English slackness—The trail of the tar—Lyddite, phenacetine, and saccharine . . 280 13