The Romance of Modern Chemistry

CONTENTS CHAPTER I THE DAWN OF CHEMISTRY PAGE Chemistry in the ancient world—The metals and the planets— Rule of thumb—Speculation versus experiment—Fire, air, earth, and water....................................17 CHAPTER II alchemy and the philosopher’s stone Chemistry in the Middle Ages—Sulphur and mercury—Trans- mutation of the metals—Apparent conversion of iron into copper—Opportunity for quack chemists—Evils of alchemy, and how it became a matter of history only . . . .21 CHAPTER III natube’s building material Animal, vegetable, and mineral—Organic and inorganic—The irreducible minimum — Elements, and how they become partners—The difference which chemical forces make— Atoms and molecules—Something beyond the power of the microscope..........................................28 CHAPTER IV INVISIBLE SUBSTANCES, AND HOW WE KNOW OF THEIR EXISTENCE Believing without seeing—How we discover gases—Hydrogen and balloons—The air we breathe—Candles and mice as danger-signals—How a gas accommodates itself to circum- stances—Restless activity where there is apparent stagnation —Gas molecule versus express train . . . . • 39 CHAPTER V ELEMENTS WITH A DOUBLE) IDENTITY How an element changes Its nature without changing Its name— Red and yellow phosphorus — Diamond and charcoal Artificial diamonds—The diamond useful as well as orna- mental— Oxygen and the “smell of electricity Two molecules which are the same externally may differ in their anatomy—A curious case of self-effacement in crystals. • 50 9