General Science by Bertha M. Clark
page 7 of 391 (01%)
page 7 of 391 (01%)
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XVIII. PUMPS AND THEIR VALUE TO MAN XIX. THE WATER PROBLEM OF A LARGE CITY XX. MAN'S CONQUEST OF SUBSTANCES XXI. FERMENTATION XXII. BLEACHING XXIII. DYEING XXIV. CHEMICALS AS DISINFECTANTS AND PRESERVATIVES XXV. DRUGS AND PATENT MEDICINES XXVI. NITROGEN AND ITS RELATION TO PLANTS XXVII. SOUND XXVIII. MUSICAL INSTRUMENTS XXIX. SPEAKING AND HEARING XXX. ELECTRICITY XXXI. SOME USES OF ELECTRICITY XXXII. MODERN ELECTRICAL INVENTIONS |
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