Chain II.
COMPOSITION AND USE OF MINERALS.
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CHAP. II.
OF THE COMPOSITION AND USE OF MINERALS.
The constituents of minerals are resolved into fifty-four elementary bodies; and these areeither gaseous, fluid, or in a solid state.
In the gaseous bodies the particles that compose them have no cohesion; they yieldreadily to pressure, and when that is removed, they expand again into their original volume.The fluids are not elastic, and do not yield to ordinary pressure.
The solids may be changed into fluids, amheat.
Gazzolytcs.
Oxygen.
Hydrogen.
Nitrogen.
Halogens.
Chlorine.
Iodine.
Bromine.
Fluorine.
Sulphur.
Selenium.
Phosphorus.
Carbon.
Boron.
Metallic Bases of the Alkalies.
Potassium.
Sodium.
Lithium.
Metallic Bases of the Alkaline Eat'ths.
Barium.
Strontium.
Calcium.
Magnesium.
fluids into gaseous Ixnlies by the agency of
Metallic Bases of the Earths.
Aluminum.
Yttrium.
Glucinum.
Zirconium.
Common Metals whose Oxides cmrnt hereduced by heat alone.
Iron.
Lead.
Copper.
Zinc.
Antimonv.
Tin.
Manganese.
Chromium.
Cobalt.
Arsenic.
Nickel.
Common Metals whose Oxidts are reducedby heat atone.
Silver.
Gold.
Platinum,
These bodies all combine with each other with reference to their weights, and theabsolute quantity of matter they contain; this constitutes the basis of the Atomic theory,proposed by the late Dr. Dalton, who established that great and important principle,which teaches that all bodies combine in definite proportions by weight, and never other-wise. Water, for instance, is composed of one volume of oxygen united with two volumesof hydrogen, the relative weights of which are as 1 to 8; the two volumes of hydrogenbeing considered as one atom or unity. All bodies which assume the gaseous form mayhave their atomic weight easily determined; carbon, for instance, which is incapable ofassuming the gaseous form, will combine with oxygen and form carbonic acid gas, onevolume of which weighs twenty-two times as much as the two volumes of hydrogen whichwe take as a standard. Twenty-two parts of carbonic acid contain sixteen of oxygen,therefore the other six must be carbon, which is the number or proportion in which thisbody combines with others. Carbonate of lime contains twenty-two parts of carbonicacid, and twenty-eight parts of lime, therefore the latter number is its atomic weight.
Atomic weights for almost all the bodies are now established, as is the relation in whichthey combine with each other; one of hydrogen combines with six of carbon, and witheight of oxygen, or, as has been stated, six of carbon combine with eight of oxygen. Theequivalent or number for water, for instance, is usually stated thus, 9 —oxygen 8 +hydro-gen 1. Sliding scales are made use of by chemists for aiding the calculations withrespect to different combinations, and it must always be borne in mind, that these
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