Calaveras
. See Sequoia
Only in Aiton's Encyclopedia
Single-source entries: C (7)
These 11 listings are so strange that each appears in only one of the 7 encyclopedias we compared. They include such classics as Calaveras, Calcareous, Calcareous Spar.
Calc-Spar
the name usually given by mineralogists to carbonate of lime, rhombohedral in its crystallization. It differs from aragonite only in crystallization. Calcite is one of the commonest minerals. Marble, for example, is composed of small crystalline granules of this mineral. It is abundantly met with in very many rocks as a secondary mineral; that is to say, it is a decomposition product the result of the chemical alteration of various rock-constituents, such as the feldspars. Thus it frequently occurs in the cracks, fissures, and vesicles of igneous rocks. The name Iceland spar has often been given to calcite, at least to the finest colorless and transparent variety, because it is found in Iceland, filling up clefts and cavities in the basalt-rocks of that region. Slate spar is a lamellar variety, often with a shining, pearly luster and a greasy feel, and is found in Wicklow in Ireland, Glen Tilt in Scotland, and Kongsberg in Norway.
Only in Collier's New Encyclopedia
Calcareous
a term applied to substances partaking of the nature of lime, or containing quantities of lime. Thus we speak of calcareous waters, calcareous rocks, calcareous soils. Calcareous spar, crystallized carbonate of lime. It is found crystallized in more than 700 different forms, all having for their primitive form an obtuse rhomboid. The rarest and most beautiful crystals are found in Derbyshire, England.
Only in Collier's New Encyclopedia
Calcareous Spar
A carbonate of lime, occurring principally in grayish-white crystals. It is infusible, falls into quicklime before the blowpipe, and effervesces with acids; its composition is lime 57, carbonic acid 43. This mineral is of universal occurrence, and sometimes it is found tinged with various shades of color, owing to the presence of manganese, iron, and other impurities.
Only in The Encyclopedia of Founding
Calcareous Tufa
a deposition from springs, streams, or underground water, from which it is precipitated partly by the escape of carbonic acid which acts as a solvent, and partly by evaporation of the water. It is usually white, creamy-white, yellowish, or brownish in color, but other hues occur, and variegated and mottled varieties are not uncommon. It is of variable texture kinds being and consistency; some rather soft, brittle, and friable, and porous or cellular. These cellular varieties have been deposited from the waters of springs, and often contain vegetable and animal remains, as leaves, twigs, nuts, moss, insects, land and fresh-water shells, etc. The so-called "petrifying springs" of Matlock afford a good example of the formation of calcareous tufa. In some regions the deposition from calcareous waters is on a very extensive scale, as along the river Anio, at Tivoli, near Rome, where calcareous tufa occurs in masses many feet in thickness. In that district the formation is harder and more compact, and under the name of travertino is used as a building stone at Rome. Calcareous tufa is abundantly deposited from thermal springs, as in the Yellowstone region of the United States. The calcareous incrustations so commonly seen in caverns in limestone rocks are varieties of calcareous tufa. They are known as stalactites and stalagmites.
Only in Collier's New Encyclopedia
Calciferous Epoch
one of the subordinate divisions of the Lower Silurian System of North America. The division is characterized by the presence of calcareous sandstones and limestones. In Scotland a subdivision of the Carboniferous system is known as the Calciferous Sandstone group.
Only in Collier's New Encyclopedia
Calcination
The process by which some bodies by the action of fire are reduced to the condition of a calx or cinder. Most of the metals can be reduced to this condition, which renders them easily reducible to powder. By subjecting ores to the action of the fire the volatile parts are driven off, and the water of crystallization dissipated. By this process marble is converted into lime by expelling the carbonic acid and water, and the same may be said of borax, gypsum, alum, and other saline substances which are deprived of their water of crystallization by the process of calcination. There is a difference between calcination and oxidation, fire being a necessary agent in the former case, while metals may be oxidated by acids, heat, or exposure to the atmosphere. See WEATHERING ORES; KILN. Calcium is a light yellow metal, somewhat harder than lead--very malleable; metals at a red heat and oxidizes in the air. It exists in abundance in limestone, fluor-spar, and gypsum. See LIME.
Only in The Encyclopedia of Founding
Calcite
CALCAREOUS SPAR, or
Only in Collier's New Encyclopedia
Calcium Carbide
chemical a compound of calcium and carbon, symbol CaC2. It is a hard, bluish-black, clear crystalline body, and is impervious to light, insoluble in all known solvents, and with a sp. gr. of 2.22. Although calcium carbide has been known for many years, it did not come into prominence until 1894, when Moissan produced it by heating 120 grains of oxide of calcium and 70 grains of sugar charcoal in an electric furnace. The furnace J was heated to 3,500° C. by an electrical current of 350 amperes and 70 volts for 20 minutes. This produced about 150 grains of carbide. Dry carbide is not affected by heat in an ordinary atmosphere, but when heated in an excess of oxygen it burns and forms calcium carbonate. When exposed to damp air for a short time it disintegrates and gives off a peculiar odor resembling garlic. When calcium carbide comes in contact with water, ACETYLENE GAS (q. v.) is produced and calcium hydroxide thrown down (CaC2+2H2O=C₂H₂+Ca (OH)2). It is used generally for the production of acetylene and the reduction of iron.
Only in Collier's New Encyclopedia
Calcium Light
a brilliant light produced by directing the flame of an oxy-hydrogen blow-pipe against a block of compressed quicklime. It has been used on the stage for many years, and by the aid of colored glasses very charming effects are produced. More recently it was employed in lanterns for projecting photographic and biographic pictures on a screen. It has now been superseded by electric light.
Only in Collier's New Encyclopedia
Calculus (Medical term for what)
the medical term for what is popularly known as stone. Calculi vary in size from a pin's head to a pigeon's egg, and even larger, and weigh from a few grains to several ounces. They derive their special name and character as well from the organs of the body in which they are found as from the constituents of which they are composed. Thus, for example, a calculus found in the kidney or ureter is called renal, in the bladder vesical, and so on; but, acording to its chemical composition, it would also be called either (1) uric (lithic) acid calculus, or (2) oxalic (mulberry) calculus, or (3) phosphatic calculus. Calculi derived from the bile are also found in the gall-bladder, and in the biliary and intestinal ducts, where they receive the name of call-stones, or biliary calculi. Those found in the salivary glands are called salivary calculi.
Only in Collier's New Encyclopedia