Pet`ro*la"tum (?), n. (Chem. & Pharm.) A semisolid unctuous substance,
neutral, and without taste or odor, derived from petroleum by
distilling off the lighter portions and purifying the residue. It is a
yellowish, fatlike mass, transparent in thin layers, and somewhat
fluorescent. It is used as a bland protective dressing, and as a
substitute for fatty materials in ointments. U. S. Pharm.
Petrolatum is the official name for the purified product. Cosmoline and
vaseline are commercial names for substances essentially the same, but
differing slightly in appearance and consistency or fusibility.
Pe*tro"le*um (?), n. [NL., fr. L. petra a rock + oleum oil: cf. F.
pÈtrole. Cf. Petrify, and Oil.] Rock oil, mineral oil, or natural oil,
a dark brown or greenish inflammable liquid, which, at certain points,
exists in the upper strata of the earth, from whence it is pumped, or
forced by pressure of the gas attending it. It consists of a complex
mixture of various hydrocarbons, largely of the methane series, but may
vary much in appearance, composition, and properties. It is refined by
distillation, and the products include kerosene, benzine, gasoline,
paraffin, etc.
Petroleum spirit, a volatile liquid obtained in the distillation of
crude petroleum at a temperature of 170∞ Fahr., or below. The term is
rather loosely applied to a considerable range of products, including
benzine and ligroin. The terms petroleum ether, and naphtha, are
sometimes applied to the still more volatile products, including
rhigolene, gasoline, cymogene, etc.
{ ||PÈ`tro`leur" (?), n. m. ||PÈ`tro`leuse" (?), n. f. }[F.] One who
makes use of petroleum for incendiary purposes.
Pet"ro*line (?), n. (Chem.) A paraffin obtained from petroleum from
Rangoon in India, and practically identical with ordinary paraffin.
{ Pet`ro*log"ic (?), Pet`ro*log"ic*al (?), } a. Of or pertaining to
petrology.
Pet`ro*log"ic*al*ly, adv. According to petrology.
Pe*trol"o*gist (?), n. One who is versed in petrology.
Pe*trol"o*gy (?), n. [Petro + -logy.] 1. The department of science
which is concerned with the mineralogical and chemical composition of
rocks, and with their classification: lithology.