Part 18
_Garnierite_ (a silicate of nickel and magnesium) is the common ore. Magnetic iron pyrite (_pyrrhotite_) often carries several per cent of nickel. Sulphides and other compounds occur. _German silver_ contains nickel, copper and zinc. It enters into other alloys.
France and Germany refine nickel from imported ore, chiefly from New Caledonia. Nickel steel, being especially hard and tough is used for armor plate, special machinery and wire rope. Nickel is extensively used for cheap electro plating.
Nickel and nickel oxide are exported to Holland and England from the United States and ores and matte are imported from Canada.
=Petroleum= (or coal oil) is obtained from wells in the United States, Russia, Dutch East Indies, Galicia, Roumania and other countries. More than half of the world’s output is from the United States, the leading districts being (1) Kansas and Oklahoma, (2) California, (3) Illinois, (4) Pennsylvania and (5) Texas. Crude oil is transported from the wells for hundreds of miles through pipe lines to the refineries.
In its crude state, petroleum is a dark colored liquid. It yields by distillation, first: light oils, _gasoline_, _naphtha_, _benzine_; second: _illuminating oils_, _kerosene_, _headlight oil_, etc.; third: _lubricating oils_, _engine oil_, _cylinder oil_, _machine oil_; fourth: _petroleum residuum_ (for asphalt paving) and _coke_. _Petrolatum_, _vaseline_ and _paraffin wax_ are by-products in petroleum refining.
American kerosene oil is exported to all parts of the globe. Crude oil is also exported as well as other petroleum products.
=Platinum= is a rare metal found with gold, iridium and other rare metals in placer mines. It comes chiefly from Russia. Smaller amounts from Colombia, California, Canada and Australia.
It is used in the terminals of incandescent electric lamps, and also employed by chemists, jewelers and dentists.
=Potash= (or potassium) is an alkaline metal. Chlorides, sulphates, etc., are found in Germany. Wood ashes and sugar beet refuse furnish much of the world’s potash. Stassfurt, Germany, possesses the only known large deposit of natural potash salts. These salts are the source of potash in many chemical industries and in fertilizers. It is exported in large amount from Germany to England, France and America.
=Quartz= (silica) is of many varieties, crystalline to amorphous.
_Rock flint_ is mined in Connecticut and Pennsylvania, and also comes from the chalk cliffs of England and France.
_Sandstones_ are quarried and used for building in almost all parts of the world. Pennsylvania, Ohio, and New York supply the greatest quantities in the United States. _Honestones_ and _whetstones_ are mostly sandstone, and in this country are largely quarried in Arkansas, Michigan and New Hampshire.
_Rock crystal_ is employed for lenses. Many semiprecious stones are varieties of quartz, as _agate_, _moss agate_, _onyx_, _sard_, _chalcedony_, _chrysoprase_, _jasper_, etc.
_Rock flint_ and _quartz sand_ are used in making glass and pottery.
Outside of building stones, quartz is used in greatest amount in making glass and pottery. For glass it is melted with alkali (soda ash) and either lime or lead oxide. Glass is either blown or molded. Belgium, Austria, Germany, France, Great Britain and the United States manufacture glassware. Pennsylvania, Indiana and New Jersey are the leading states.
=Radium= is the most characteristic of those substances which possess the property of radio-activity--i.e. have the power of producing photographic or electric effects by a process identical with or analogous to radiation. The property was first observed in _uranium_ by Becquerel in 1896--hence the name “Becquerel rays.” In 1898 Schmidt and Madame Curie discovered almost simultaneously that the compounds of _thorium_ had the same radio-active property; and further elaborate investigations led to the discovery of _polonium_, _radium_, and _actinium_, as new substances with radio-active properties. Polonium was the name given by M. and Mme. Curie to the radio-active component of bismuth separated from pitchblende. Its activity is transient. In the new field of research thus opened up important work has been done by Rutherford, Crooks, Ramsay, Soddy, Huggins, and others.
Radium is derived from _pitchblende_, in which it exists in very small quantities. After a long-continued process of fractional crystallization it has been prepared in the form of a tolerably pure salt. The process of obtaining the element is very tedious. One to two kilograms of impure radium bromide can be procured from a ton of pitchblende residue only after processes extending over months. For the remarkable chemical properties of radium, see further under Radio-activity.
=Rare Metals.= These include chiefly the following: _Tungsten_, _molybdenum_, _vanadium_ and _uranium_. They are found in Colorado, Arizona, Germany, England and Sweden. The ores of these metals are unusual minerals, and the metals themselves are used in making special high grades of steel. Their salts are used in dyeing.
_Thorium_, _cerium_, _lanthanum_ and _yttrium_, found in North Carolina, Norway, Brazil and Ceylon, are also to be classified under this head. Monazite, samarskite, thorite and other rare minerals contain these elements. They are used in preparing the mantles for incandescent gas lights.
=Silver=, the more common precious metal, is produced in greatest amount in the Rocky Mountains and the Andes. The United States, Mexico, Australia, Bolivia, Chili, Peru and Germany contribute nearly the entire supply. Montana, Colorado, Nevada and Utah lead in silver production in the United States. The ores are usually smelted and refined to purify the metal.
_Argentiferous galena_ (lead ore) is the commonest ore of silver. The amount of silver per ton varies greatly. Zinc and copper ores often carry silver. Many sulphides of silver (argentite, pyrargyrite, etc.) are found, as well as chlorides and bromides (cerargyrite and bromyrite). _Chloride_ and _nitrate of silver_ are used in photography.
Silver is manufactured into innumerable articles for household use and personal adornment. The cheapest articles are not solid (sterling) but are electrically plated with a very thin coating of silver. Silver coins form the bulk of the currency of the world, although in most countries gold is the standard.
=Sodium= is the most important alkaline metal, and has a wide use.
_Salt_ (rock salt, sea salt, lake salt, halite or sodium chloride) is the commonest natural compound of sodium. Important for food and in chemical manufacture.
Rock salt is mined in Germany, Austria, Spain, England, Louisiana, Kansas, India and other parts of the world. Obtained by evaporating salt water from wells in England, Michigan, New York, Ohio and China, or by evaporating salt water in the West Indies, Great Salt Lake, etc.
Besides its use for meat packing, curing fish, domestic purposes, etc., it is employed in silver refining, and the preparation of hydrochloric acid, soda ash, carbonate of soda and other chemical products.
_Soda niter_ (nitrate of sodium) is a very easily soluble mineral. It is found in quantity only in the deserts of northern Chili, and is exported in large amounts to Europe and America for fertilizer and the manufacture of nitric acid and other chemicals.
_Borax_ (hydrous sodium borate) occurs in nature in an impure form and is prepared also from calcium borates. Borates are found in Tuscany, Central Asia, California and Nevada, and in South America.
Borax and boracic acid are used in pottery manufacture, for the preservation of meat, in dyeing and in medicine.
=Strontium= is found in Germany, Scotland, Texas and New York. Strontianite (strontium carbonate) and celestite (strontium sulphate) contain this element. Strontium salts are used in sugar refining and making red fire.
=Sulphur= or brimstone is found in a pure state in volcanic regions or associated with gypsum and limestone. Pyrite (sulphide of iron) is also a source of sulphur compounds.
Sicily, Italy, Japan, Louisiana and Utah have mines of native sulphur, which is used in manufacturing sulphuric acid, gunpowder, matches, as a disinfectant, for bleaching and vulcanizing rubber.
Blue vitriol, green vitriol and alum are sulphates. Sulphur is imported from Sicily and Italy.
=Thorium.= See rare metals.
=Tin= is less abundant than most of the common metals. The Malay peninsula and nearby islands (Banca and Billiton) produce over half the tin ore of the world. The remainder is mined in Bolivia, Australia, Tasmania and Cornwall, England. Small deposits occur in the United States.
Tin melts at a low temperature and is easily refined.
_Cassiterite_ (tin oxide) is the only important ore. This mineral is commonly found as pebbles (stream tin) in gravel.
_Tinplate_ and alloys containing tin are of enormous importance in the arts. Of these, _bronze_ is chief. _Gun metal_, _pewter_, _solder_, _type metal_ and _britannia metal_ are other alloys. Salts of tin are used in dyeing, glass making, etc.
Tinplate, used for tin cans, roofing and kitchen utensils, is made by dipping sheet iron or steel in a bath of melted tin, thus covering it with a thin layer of tin. Tinplate is manufactured in the United States and imported from England. Tin metal is imported from England and Straits Settlements.
=Tungsten.= See rare metals.
=Uranium.= See rare metals.
=Vanadium.= See rare metals.
=Zinc= is one of the most useful metals. Germany, United States and Belgium supply most of the zinc. In this country, Missouri and Kansas lead in zinc production.
_Sphalerite_ or blend (zinc sulphide) is the chief ore. Carbonates, silicates and oxides of zinc are found. Crude zinc (_spelter_) is distilled from roasted ore.
_Brass_, _German silver_ and other alloys contain zinc. _Galvanized iron_ consists of a coating of zinc on sheet iron. _Zinc oxide_ (zinc white) resembles white lead and is used in paints.
Used in electric batteries, making hydrogen, zinc etchings, etc. The greatest amount of zinc is used in alloys and zinc compounds. Zinc and zinc ores are both imported and exported by the United States, the imports exceeding the exports. Zinc oxide is exported in larger amount than any other form.
[Illustration: =HOW AND WHERE WE GET THE SALT FOR OUR FOOD=
=THE PRODUCTIVE CALIFORNIA SALT BEDS=
The United States produces one-fourth of the entire output of the world. Salt was one of the first two great articles of international commerce in the history of the world trade.]
[Illustration: =AN UNDERGROUND PASSAGE WAY THROUGH SOLID SALT=
The most wonderful salt mines in the world are those of Galicia, in Austria. In this region there is a mass of salt estimated to measure 500 miles in length, 20 miles in breadth, and 1,200 feet in thickness.]
SCIENTIFIC TERMS USED IN THE EARTH SCIENCES
=Acanthodus= (_a-kan-thō´dus_).--Fossil fish, having thorn-like fins.
=Aërodynamics= (_ā-ẽr-ō-di-nam´iks_).--The science which treats of the air and other gaseous bodies under the action of force, and of their mechanical effects.
=Aërognosy= (_ā-ẽr-ŏg´nô-sy_̆).--The science which treats of the properties of the air, and of the part it plays in nature.
=Aërolite= (_ā´ẽr-ô-līt_).--A stone, or metallic mass, which has fallen to the earth from distant space; a meteorite; a meteoric stone.
=Aërology= (_ā-ẽr-ŏl´ôjy̆_).--That department of physics which treats of the atmosphere.
=Aerometer= (_ā´ẽr-ŏm´ê-tẽr_).--An instrument for ascertaining the weight or density of air and gases.
=Ammonites= (_am´mo-nitz_).--Fossil mollusks of spiral form, found in all strata from the palæozoic to the chalk; very numerous, varying greatly in size; all now extinct; sometimes called snakestones.
=Anemology= (_ăn-ĕ-mŏl´ô-jy̆_).--The science of the wind.
=Anemometer= (_ăn-ĕ-mŏm´ẽ-tẽr_).--An instrument for measuring the force and velocity of the wind; a wind gauge.
=Attrition= (_ăt-trĭsh´ŭn_).--The act of rubbing together; friction; the act of wearing by friction, or by rubbing substances together; abrasion.
=Aurora= (_aw-rō´rȧ_).--The rising light of the morning; the dawn of day; the redness of the sky just before the sun rises.
=Aurora Borealis= (_bō´rẽ-ā´lĭs_), i. e., northern daybreak; popularly called northern lights. A luminous m