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An oily, volatile hydrocarbon, obtained by the distillation of caoutchouc or guttaipercha.C5H8 -- unsaturated, and used to make synthetic rubber by polymerization. In organic chemistry, viewed conceptually as the building block of the terpene series of hydrocarbons

A crystalline hydrocarbon derivative, metameric with orcin, but produced artificially; -- called also cresorcin.

ly by the distillation and purification of petroleum. It consists chiefly of several hydrocarbons of the methane series.

dehydes, obtained by the distillation of certain salts of organic acids and consisting of carbonyl (CO) united with two hydrocarbon radicals. In general the ketones are colorless volatile liquids having a pungent ethereal odor.

e urine of dogs. By decomposition the acid yields a nitrogenous base (called kynurin) and carbonic acid. [Written also cynurenic.]

mphibia, including the typical genus Labyrinthodon, and many other allied forms, from the Carboniferous, Permian, and Triassic formations. By recent writers they are divided into two or more orders. See Stegocephala.

cticum or lactis), which produces lactic fermentation, decomposing the sugar of milk into carbonic and lactic acids, the latter, of which renders the milk sour, and precipitates the casein, thus giving rise to the so- called spontaneous coagulation of milk. -- Lactic fermentation. See under Fermentation.…

The fine impalpable soot obtained from the smoke of carbonaceous substances which have been only partly burnt, as in the flame of a smoking lamp. It consists of finely divided carbon, with sometimes a very small proportion of various impurities. It is used as an ingredient of printers' ink, and various black pigments a…

Hydrous carbonate of lanthanum, found in tabular while crystals.

, to cast the sounding lead for ascertaining the depth of water. -- White lead, hydrated carbonate of lead, obtained as a white, amorphous powder, and much used as an ingredient of white paint.

A mineral of a yellowish or greenish white color, consisting of the sulphate and carbonate of lead; -- so called from having been first found at Leadhills, Scotland.

A genus of fossil trees of the Devonian and Carboniferous ages, having the exterior marked with scars, mostly in quincunx order, produced by the separation of the leafstalks.

btained in refining crude petroleum. It is a complex and variable mixture of several hydrocarbons, generally boils below 170º Fahr., and is more inflammable than safe kerosene. It is used as a solvent, as a carburetant for air gas, and for illumination in special lamps.

usually called quicklime, obtained by calcining limestone or shells, the heat driving off carbon dioxide and leaving lime. It develops great heat when treated with water, forming slacked lime, and is an essential ingredient of cement, plastering, mortar, etc.CaO

A rock consisting chiefly of calcium carbonate or carbonate of lime. It sometimes contains also magnesium carbonate, and is then called magnesian or dolomitic limestone. Crystalline limestone is called marble.

among living animals the genus Limulus, with various allied fossil genera, mostly of the Carboniferous period. Called also Xiphosura.

ne scales, by heating lead moderately in a current of air or by calcining lead nitrate or carbonate. It is used in making flint glass, in glazing earthenware, in making red lead minium, etc. Called also massicot.

ra tartarea, etc.), as a blue amorphous mass which consists of a compound of the alkaline carbonates with certain coloring matters related to orcin and orcein.

te substance, consisting of magnesium oxide, and obtained by heating magnesium hydrate or carbonate, or by burning magnesium. It has a slightly alkaline reaction, and is used in medicine as a mild antacid laxative. See Magnesium. Magnesia alba Etym: [L.] (Med. Chem.), a bulky white amorphous substance, consisting of a…

Native magnesium carbonate occurring in white compact or granular masses, and also in rhombohedral crystals.