Part 951

Hy`dro*car"bon*ate (?), n. (a) (Old Chem.) A hydrocarbon. [Obs.] (b) (Chem.) A hydrous carbonate, as malachite.

Hy`dro*car`bo*sty"ril (?), n. [Hydro-, 2 + carbostyril.] (Chem.) A white, crystalline, nitrogenous hydrocarbon, C9H9NO, obtained from certain derivatives of cinnamic acid and closely related to quinoline and carbostyril.

Hy`dro*car"bu*ret (?), n. [Hydro- , 2 + carburet.] (Chem.) Carbureted hydrogen; also, a hydrocarbon. [Obs.]

Hy`dro*cau"lus (?), n.; pl. Hydrocauli (#). [NL., fr. Gr. "y`dwr water + &?; a stalk.] (Zoˆl.) The hollow stem of a hydroid, either simple or branched. See Illust. of Gymnoblastea and Hydroidea.

Hy`dro*cele (?), n. [L., fr. Gr. &?;; "y`dwr water + &?; tumor.] (Med.) A collection of serous fluid in the areolar texture of the scrotum or in the coverings, especially in the serous sac, investing the testicle or the spermatic cord; dropsy of the testicle.

Hy`dro*ce*phal"ic (?), a. Relating to, or connected with, hydrocephalus, or dropsy of the brain.

Hy`dro*ceph"a*loid (?), a. [Hydrocephalus + -oid.] (Med.) Resembling hydrocephalus.

Hydrocephaloid affection (Med.), the group of symptoms which follow exhausting diarrhea in young children, resembling those of acute hydrocephalus, or tubercular meningitis.

Hy`dro*ceph"a*lous (?), a. Having hydrocephalus. "Hydrocephalous offspring." G. Eliot.

Hy`dro*ceph"a*lus (?), n. [NL., fr. Gr. &?; hydrocephalus; "y`dwr water + &?; head.] (Med.) An accumulation of liquid within the cavity of the cranium, especially within the ventricles of the brain; dropsy of the brain. It is due usually to tubercular meningitis. When it occurs in infancy, it often enlarges the head enormously.

Hy`dro*chlo"rate (?), n. (Chem.) Same as Hydrochloride.

Hy`dro*chlo"ric (?), a. [Hydro-, 2 + chloric: cf. F. hydrochlorique.] (Chem.) Pertaining to, or compounded of, chlorine and hydrogen gas; as, hydrochloric acid; chlorhydric.

Hydrochloric acid (Chem.), hydrogen chloride; a colorless, corrosive gas, HCl, of pungent, suffocating odor. It is made in great quantities in the soda process, by the action of sulphuric acid on common salt. It has a great affinity for water, and the commercial article is a strong solution of the gas in water. It is a typical acid, and is an indispensable agent in commercial and general chemical work. Called also muriatic, ∧ chlorhydric, acid.

Hy`dro*chlo"ride (?), n. (Chem.) A compound of hydrochloric acid with a base; -- distinguished from a chloride, where only chlorine unites with the base.

||Hy`dro*co*ral"li*a (?), n. pl. [NL. See Hydra, and Coral.] (Zoˆl.) A ||division of Hydroidea, including those genera that secrete a stony ||coral, as Millepora and Stylaster. Two forms of zooids in life ||project from small pores in the coral and resemble those of other ||hydroids. See Millepora.

Hy`dro*cy"a*nate (?), n. (Chem.) See Hydrocyanide.

Hy`dro*cy*an"ic (?), a. [Hydro-, 2 + anic: cf. F. hydrocyanique.] (Chem.) Pertaining to, or derived from the combination of, hydrogen and cyanogen.

Hydrocyanic acid (Chem.), a colorless, mobile, volatile liquid, HCN, having a characteristic peach-blossom odor. It is one of the most deadly poisons. It is made by the action of sulphuric acid on yellow prussiate of potassium (potassium ferrocyanide), and chemically resembles hydrochloric and hydrobromic acids. Called also prussic acid, hydrogen cyanide, etc.

Hy`dro*cy"a*nide (?), n. (Chem.) A compound of hydrocyanic acid with a base; -- distinguished from a cyanide, in which only the cyanogen so combines.

{ Hy`dro*dy*nam"ic (?), Hy`dro*dy*nam"ic*al (?), } a. [Hydro-, 1 + dynamic, - ical: cf. F. hydrodynamique.] Pertaining to, or derived from, the dynamical action of water of a liquid; of or pertaining to water power.

Hydrodynamic friction, friction produced by the viscosity of a liquid in motion.

Hy`dro*dy*nam"ics (?), n. [Hydro- , 1 + dynamics: cf. F. hydrodynamique.] That branch of the science of mechanics which relates to fluids, or, as usually limited, which treats of the laws of motion and action of nonelastic fluids, whether as investigated mathematically, or by observation and experiment; the principles of dynamics, as applied to water and other fluids.

The word is sometimes used as a general term, including both hydrostatics and hydraulics, together with pneumatics and acoustics. See Hydraulics.

Hy`dro*dy`na*mom"e*ter (?), n. [Hydro-, 1 + dynamometer.] An instrument to measure the velocity of a liquid current by the force of its impact.

Hy`dro-e*lec"tric (?), a. [Hydro- , 1 + electric.] Pertaining to, employed in, or produced by, the evolution of electricity by means of a battery in which water or steam is used.

Hydro-electric machine (Physics), an apparatus invented by Sir William Armstrong of England for generating electricity by the escape of high-pressure steam from a series of jets connected with a strong boiler, in which the steam is produced.

Hy`dro-ex*tract"or (?), n. [Hydro- , 1 + extractor.] An apparatus for drying anything, as yarn, cloth, sugar, etc., by centrifugal force; a centrifugal.

Hy`dro*fer`ri*cy*an"ic (?), n. [Hydro-, 2 + ferricyanic.] (Chem.) Pertaining to, or containing, or obtained from, hydrogen, ferric iron, and cyanogen; as, hydroferricyanic acid. See Ferricyanic.