CHAPTER LV

CHEMISTRY We have traveled far since Chemistry had as its simple basis four elements: fire, air, water, and earth, regarded as perfect and complete since they embody every essence of which a body was supposedly capable: for fire was hot and dry; air, hot and wet; water, cold and wet; earth, cold and dry. We have outlived the belief in the philosopher’s stone which animated the Middle Ages. Yet these fallacies are but manifestations of the effort—old as thought—to reduce the manifoldness of matter to primordial elements, from which, in one form or other, every substance should be capable of being built up. The ultimate problem of chemistry is, therefore, the constitution of matter, and the fight around this is waged on the marches of the physical and chemical sciences. [Sidenote: Triumphs of Chemistry] The great commercial triumphs of chemistry are, of course, those due to the conquest of waste, to the utilization of by-products which for thousands of years had been regarded as useless. We are all familiar with the uses to which the by-products of coal-tar are put; we swallow one derivative to relieve headache, we may sugar our tea and flavour our ice-cream with others; with one derivative we clean our clothes which have been dyed with others; and we disinfect them with yet another. Phenacetin, saccharin, synthetic vanilla, benzine, naphthaline, analine dyes, carbolic acid, are only a few of the many substances won to the consumer by the chemist in his laboratory; and this is only one field of research. The chemist is always busy (as now with rubber, camphor, etc.), working at the synthesis of natural products in the hope that he will be able to find a means of manufacturing them in quantities at a cost which will make them, commercially possible, and thus lessen the drain on the world’s natural supply. In almost every detail of our lives this science enters so familiarly that we forget that the many things made possible by the chemist do not simply “happen,” but are the result of laborious research in the laboratory. It is not possible to attain proficiency in any experimental science without laboratory work; but to the student of chemistry the lucid and original articles in the Britannica will provide a most useful commentary on his work with test-tube and burner. The general reader will find in these articles an admirable survey of the subject, and of its bearings on problems of daily life. The main article CHEMISTRY (Vol. 6, p. 33) generally covers the ground, and serves as an introduction to separate articles on important divisions of the subject. Following its arrangement the scheme outlined below suggests a useful course of reading. (i.) Chemistry, _History_ (Vol. 6, p. 33). Supplementary to this section are the articles ALCHEMY (Vol. 1, p. 519), ELEMENT (Vol. 9, p. 253), MOLECULE (Vol. 18, p. 654), ATOM (Vol. 2, p. 870); and reference may also be made to MEDICINE, _Iatro-chemical School_ (Vol. 18, p. 50). (ii.) Chemistry, _General Principles_ (Vol. 6, p. 39), with reference to VALENCY (Vol. 27, p. 847), CHEMICAL ACTION (Vol. 6, p. 26), CATALYSIS (Vol. 5, p. 501), ISOMERISM (Vol. 14, p. 881), STEREO-ISOMERISM (Vol. 25, p. 890), RADIOACTIVITY (Vol. 22, p. 793). (iii.) _Inorganic Chemistry_ (Vol. 6, p. 44). See also ACID (Vol. 1, p. 145), ALKALI (Vol. 1, p. 674), and the list of 138 elements and compounds under this heading below. (iv.) _Organic Chemistry_ (Vol. 6, p. 47), with all the 240 articles enumerated under this heading below, especially that on POLYMETHYLENES (Vol. 22, p. 29); see also EXPLOSIVES (Vol. 10, p. 81). (v.) _Analytical Chemistry_ (Vol. 6, p. 60), with which may be consulted, BLOW PIPE (Vol. 4, p. 89), DISTILLATION (Vol. 8, p. 318), ELECTROLYSIS (Vol. 9, p. 217), INDICATOR (Vol. 14, p. 482), SOLUTION (Vol. 25, p. 368), STOICHIOMETRY (Vol. 25, p. 939). (vi.) _Physical Chemistry_ (Vol. 6, p. 65) supplemented by ENERGETICS (Vol. 9, p. 390), CHEMICAL ACTION (Vol. 6, p. 26), THERMOCHEMISTRY (Vol. 26, p. 804), SOLUTION (Vol. 25, p. 368), DISTILLATION (Vol. 8, p. 318), CONDENSATION OF GASES (Vol. 6, p. 844), with the important articles PHOTOCHEMISTRY (Vol. 21, p. 484), ELECTROCHEMISTRY (Vol. 9, p. 208), METALLURGY (Vol. 18, p. 203), ELECTROMETALLURGY (Vol. 9, p. 232), ASSAYING (Vol. 2, p. 776). Among the contributors to the chemical department of the Britannica are: Professor Ernest Rutherford, of the University of Manchester; Walter Nernst, professor of physical chemistry in the University of Berlin; W. C. D. Whetham, author of _Theory of Solution_, etc.; Prof. James Walker of the University of Edinburgh; Johannes Diderik van der Waals, professor of physics, University of Amsterdam; W. R. E. Hodgkinson, professor of chemistry and physics, Ordnance College, Woolwich, perhaps the greatest living authority on explosives. The following is a classified list of the articles on Chemistry which are contained in the Britannica. For discussions of the application of chemistry to photography, the reader should consult the article PHOTOGRAPHY (Vol. 21, p. 485), of which the chemical section is by Sir W. de W. Abney, adviser in Science to the English Board of Education. CHEMISTRY—GENERAL Affinity, Chemical Alchemy Alembic Allotropy Amorphism Analysis Assaying Atmolysis Atom Blowpipe Catalysis Chemical Action Chemistry Combustion Condenser Crystallization Decolourizing Desiccation Dialysis Dissociation Distillation Electrochemistry Electrolysis Element Elixir Equivalent Explosives Flame Formula Gas Hydrolysis Iatrochemistry Indicator Isomerism Matrass Molecule Photochemistry Pigments Pyrophorus Radioactivity Solution Stereochemistry Stereo-isomerism Stoichiometry Thermochemistry Valency INORGANIC CHEMISTRY Acid Algaroth, Powder of Alkali Alkali Manufacture Alkaline Earths Alum Aluminium Amalgam Ammonia Antimony Argon Arsenic Azoimide, or Hydrazoic Acid Azoth Barium Base Beryllium, or Glucinum Bichromates and Chromates Bismuth Bittern Borax Boric Acid, or Boracic Acid Boron Brimstone Bromine Cadmium Caesium Calcium Calomel Carbide Carbon Carbonates Carbon Bisulphide Carbonic Acid Carborundum Caustic Cerium Charcoal Chlorates Chlorine Chromium Cobalt Colcothar Columbium, or Niobium Copper Copperas Corrosive Sublimate Didymium Earth Epsom Salts Erbium Europium Fluorine Gadolinium Gallium Germanium Glauber’s Salt Glucinum Gold Gunpowder Halogens Hartshorn, Spirits of Helium Hydrate Hydrazine Hydrochloric Acid Hydrogen Hydroxylamine Hyposulphite of Soda Ice Indium Iodine Iron Kelp Kermes Lamp-black Lanthanum Lead Lime Lithium Magnesium Manganese Mercury Microcosmic Salt Molybdenum Nickel Niobium Nitre Nitric Acid Nitrogen Ochres Orpiment Osmium Oxide Oxygen Oxyhydrogen Flame Ozone Palladium Phosphates Phosphorus Plaster of Paris Platinum Potashes Potassium Radium Rare Earths Rhodium Rouge Rubidium Rust Ruthenium Sal Ammoniac Salt Saltpetre Samarium Scandium Schlippe’s Salt Selenium Silica Silicon Silver Sodium Steam Strontium Sulphur Sulphuric Acid Tantalum Tellurium Terbium Thallium Thorium Tin Titanium Tungsten Ultramarine Umber Uranium Vanadium Vermilion Vitriol Ytterbium (Neo-ytterbium) Yttrium Zinc Zirconium ORGANIC CHEMISTRY Acenaphthene Acetic Acid Aceto-acetic Ester Acetone Acetophenone Acetylene Acid Amides Acridine Adenine Adipocere Albumin, or Albumen Alcohol Alcohols Aldehydes Alizarin Alkahest Alkaloid Alkanet Allantoin Alloxan Alloxantin Allyl Alcohol Amidines Amines Amygdalin Amyl Alcohols Amyl Nitrate Aniline Anthracene Anthraquinone Antipyrine Argol Asparagine Azo Compounds Azoximes Benzaldehyde Benzene Benzidine Benzoic Acid Benzoin Benzophenone Benzyl Alcohol Berberine Betaïne Brucine Butyl Alcohols Butyric Acid Caffeine Camphors Carbazol Carbohydrate Carbolic Acid, or Phenol Carvacrol Cellulose Chloral Chloroform Chlorophyll Chlorpicrin Chrysene Cinnamic Acid Cinnolin Citric Acid Coal-tar Cocaine Collodion Conine Coumarin Coumarones Creosote Cresols Crotonic Acid Cyanamide Cyanic Acid and Cyanates Cyanide Cyanogen Cytisine Dextrine Diazo Compounds Diphenyl Durene Dynamite Ecgonine Erythrite Esters Ether Ethers Ethyl Ethyl chloride Ethylene Eugenol Eupion Flavin Fluoranthene Fluorene Fluorescein Formalin, or Formaldehyde Formic Acid Fructose, or Fruit-sugar Fuchsine Fulminic Acid Fumaric and Maleic Acids Furazanes Furfurane, or Furane Fusel Oil Gallic Acid Gelatin or Gelatine Glucose Glucoside Glutaric Acid Glycerin Glycols Guanidine Guncotton Hippuric Acid Hydantoin Hydracrylic Acid Hydrastine Hydrazone Hydrocarbon Imidazoles or Glyoxalines Indazoles, or Glyoxalines Indazoles Indene Indigo Indole Indulines Inulin Iodoform Isatin Isoxazoles Ketenes Ketones Lactic Acid Lactones Laevulinic Acid Litmus Malic Acid Malonic Acid Mandelic Acid Marsh Gas Mellitic Acid Mercaptans Mesoxalic Acid Methyl Alcohol Mucic Acid Murexide Mustard Oils Naphtha Naphthalene Naphthols Naphthylamines Nicotine Nitrobenzene Nitro Compounds Nitroglycerin Olefine Oleic Acid Orcin Oxalic Acid Oxazoles Oximes Palmitic Acid Paraffin Paraldehyde Phenacetin Phenanthrene Phenazine Phenolphthalein Phthalazines Phthalic Acids Picene Picric Acid Pilocarpine Piperazin Piperine Piperonal Polymethylenes Primuline Propiolic Acid Propyl Alcohols Prussic Acid Purin Pyrazines Pyrazoles Pyrene Pyridine Pyrimidines Pyrocatechin Pyrogallol Pyrones Pyrrol Pyruvic Acid Quercitron Quinazolines Quinoline Quinones Quinoxalines Resorcin Retene Saccharic Acid Saccharin Safranine Salicylic Acid Stearic Acid Styrolene Succinic Acid Sugar Sulphonal Sulphonic Acids Tannin or Tannic Acid Tar Tartar Tartaric Acid Terpenes Tetrazines Tetrazoles Thiazines Thiazoles Thiophen Thymol Toluene Triazines Triazoles Triphenylmethane Tropine Urea, or Carbamide Urethane Uric Acid Urotropin Valeric Acid Verdigris Veronal Xanthic Acid Xanthone Xylene BIOGRAPHIES Abel, Sir Frederick A. Achard, F. C. Andrews, Thomas Baeyer, Adolf von Balard, Antoine J. Baumé, Antoine Becher, J. J. Bell, Jacob Bergman, Torbern Olof Berthelot, M. P. E. Berthollet, C. L. Berzelius, J. J. Black, Joseph Boussingault Brande, William Thomas Brown, S. M. Bunsen, R. W. von Calvert, F. Crace Cannizzaro, Stanislao Cavendish, Henry Chevreul, M. E. Clark, Thomas Crookes, Sir William Dalton, John Daniell, John F. Davy, Sir Humphry Dewar, Sir James Döbereiner, J. W. Dulong, Pierre Louis Dumas, J. B. A. Erdmann, Otto Linné Fehling, Hermann von Fischer, Emil Fittig, Rudolf Flamel, Nicolas Fourcroy, A. F., de Frankland, Sir Edward Frémy, Edmond Fresenius, Karl R. Friedel, Charles Fuchs, Johann N. von Gannal, J. N. Gay-Lussac, J. L. Geber Geoffroy, E. F. Gerhardt, Charles F. Gibbs, Oliver Wolcott Gilbert, Sir Joseph H. Gladstone, John Hall Glaser, Christopher Glauber, Johann R. Gmelin (family) Graham, Thomas Guimet, Jean B. Guyton de Morveau Harcourt, W. Vernon Helmont, Jean B. van Henry, William Hofmann, A. W. von Homberg, William Kekulé, F. August Klaproth, M. H. Kolbe, A. W. Hermann Kopp, Hermann F. M. Kunkel von Lowenstjern Lavoisier, A. L. LeBlanc, Nicolas Lemery, Nicolas Liebig, J. von, baron Lunge, Georg Magnus, H. G. Marggraf, Andreas S. Marignac, J. C. G. de Mayow, John Mendeléeff, Dmitri I. Meyer, J. Lothar Meyer, Victor Mitscherlich, E. Mohr, K. Friedrich Moissan, Henri Mond, Ludwig Murray, John Muspratt, J. and J. S. Newlands, John A. R. Nobel, Alfred B. Pasteur, Louis Pelouze, T. Jules Perkin, Sir W. H. Pettenkofer, M. J. von Plattner, K. F. Priestley, Joseph Proust, Joseph Louis Prout, William Ramsay, Sir William Raoult, François M. Regnault, H. V. Richter, J. B. Roebuck, John Roscoe, Sir H. E. Rose (family) Rouelle, G. F. Sainte-Claire Deville Scheele, K. W. Schönbein, C. F. Schützenberger, P. Silliman, Benjamin Stahl, G. E. Stas, J. S. Tennant, Charles Tennant, Smithson Thénard, L. J. Thomsen, Julius Thomson, Thomas Van’t Hoff, J. H. Vauquelin, L. N. Weldon, Walter Wenzel, K. F. Williamson, A. W. Wislicenus, J. Wöhler, Friedrich Wollaston, W. H. Wurtz, C. A. Young, James