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A dyestuff, resembling alizarin, obtained from naphthoquinone as a red crystalline substance with a bright green, metallic luster; -- called also naphthalizarin.

a series of hydroxyl derivatives of naphthalene, analogous to phenol. In general they are crystalline substances with a phenol (carbolic) odor. Naphthol blue, Naphthol orange, Naphthol yellow (Chem.), brilliant dyestuffs produced from certain complex nitrogenous derivatives of naphthol or naphthoquinone.…

A yellow crystalline substance, C10H6O2, analogous to quinone, obtained by oxidizing naphthalene with chromic acid.

One of two basic amido derivatives of naphthalene, C10H7.NH2, forming crystalline solids.

An alkaloid found in small quantities in opium, and extracted as a white crystalline substance of a bitter astringent taste. It is a narcotic. Called also narceia.

An alkaloid found in opium, and extracted as a white crystalline substance, tasteless and less poisonous than morphine; -- called also narcotia.

A bitter crystalline substance constituting the essential principle of Natal aloes. Cf. Aloon.

A zeolite occuring in groups of glassy acicular crystals, and in masses which often have a radiated structure. It is a hydrous silicate of alumina and soda.

Any slender, pointed object, like a needle, as a pointed crystal, a sharp pinnacle of rock, an obelisk, etc. Dipping needle. See under Dipping. -- Needle bar, the reciprocating bar to which the needle of a sewing machine is attached. -- Needle beam (Arch.), to shoring, the horizontal cross timber which goes through t…

A mineral occuring at Vesuvius, in glassy agonal crystals; also elsewhere, in grayish or greenish masses having a greasy luster, as the variety elæolite. It is a silicate of aluminia, soda, and potash.

nge. It has a strong odor, and is used in perfumery, etc. Neroli camphor (Chem.), a white crystalline waxy substance, tasteless and odorless, obtained from beroli oil; -- called also auradin.

refraction of proteid matter. It was for a long time considered identical with choline, a crystalline body originally obtained from bile. Chemically, however, choline is oxyethyl-trimethyl-ammonium hydroxide, while neurine is vinyl-trimethyl-ammonium hydroxide. [Written also neurin.]

A white crystalline semitransparent salt; potassium nitrate; saltpeter. See Saltpeter.

Of, pertaining to, or designating, a complex organic acid produced as a white crystalline substance by the action of nitrous acid on hydroquinone.

Any one of a series of nitro derivatives of aniline. In general they are yellow crystalline substances.

A salt of nitric acid. Nitrate of silver, a white crystalline salt (AgNO3), used in photography and as a cauterizing agent; -- called also lunar caustic.

A mineral occurring in transparent crystals, usually of a white, sometimes of a reddish gray, or lemon-yellow, color; native sodium nitrate. It is used in making nitric acid and for manure. Called also soda niter.

eing a strong acid, and in decomposition a strong oxidizer. -- Nitric anhydride, a white crystalline oxide of nitrogen (N2O5), called nitric pentoxide, and regarded as the anhydride of nitric acid. -- Nitric oxide, a colorless poisous gas (NO) obtained by treating nitric acid with copper. On contact with the air or w…

A nitro derivative of methane, analogous to chloroform, obtained as a colorless oily or crystalline substance, CH.(NO2)3, quite explosive, and having well-defined acid properties.

Any one of a series of nitro derivatives of phenol. They are yellow oily or crystalline substances and have well-defined acid properties, as picric acid.