Hydrometric pendulum, a species of hydrometer consisting of a hollow
ball of ivory or metal suspended by a treated from the center of a
graduated quadrant, and held in a stream to measure the velocity of the
water by the inclination given to the thread; a kind of current gauge.
Hy`dro*met"ro*graph (?), n. [Hydro- , 1 + Gr. &?; measure + -graph.] An
instrument for determining and recording the quantity of water
discharged from a pipe, orifice, etc., in a given time.
Hy*drom"e*try (?), n. [Cf. F. hydromËtrique.] 1. The art of determining
the specific gravity of liquids, and thence the strength of spirituous
liquors, saline solutions, etc.
2. The art or operation of measuring the velocity or discharge of
running water, as in rivers, etc.
Hy`dro*mi"ca (?), n. [Hydro-, 1 + mica.] (Min.) A variety of potash
mica containing water. It is less elastic than ordinary muscovite.
Hydromica schist (Min.), a mica schist characterized by the presence of
hydromica. It often has a silky luster and almost soapy feel.
||Hy`dro*ne*phro"sis (?), n. [NL., Gr. "y`dwr water + &?; a kidney.]
||(Med.) An accumulation of urine in the pelvis of the kidney,
||occasioned by obstruction in the urinary passages.
Hy"dro*path (?), n. [Cf. F. hydropathe.] A hydropathist.
{ Hy`dro*path"ic (?), Hy`dro*path"ic*al (?), } a. Of or pertaining to
hydropathy.
Hy*drop"a*thist (?), n. One who practices hydropathy; a water-cure
doctor.
Hy*drop"a*thy (?), n. [Hydro-, 1 + Gr. &?;, &?;, to suffer.] The water
cure; a mode of treating diseases by the copious and frequent use of
pure water, both internally and externally.
||Hy`dro*per`i*to*ne"um (?), n. [NL. See Hydro-, and Peritoneum.]
||(Med.) Same as Ascites.
Hy"dro*phane (?), n. [Hydro-, 1 + Gr. &?; to show, appear: cf. F.
hydrophane.] (Min.) A semitranslucent variety of opal that becomes
translucent or transparent on immersion in water.
Hy*droph"a*nous (?), a. (Min.) Made transparent by immersion in water.
Hy"dro*phid (?), n. [Hydro-, 1 + Gr. &?; a small serpent.] (Zoˆl.) Any
sea snake of the genus Hydrophys and allied genera. These snakes are
venomous, live upon fishes, and have a flattened tail for swimming.
Hy`dro*phlo"rone (?), n. [Hydro- , 2 + phlorone.] (Chem.) A white,
crystalline benzene derivative, C8H10O2, obtained by the reduction of
phlorone.
Hy`dro*pho"bi*a (?), n. [L., fr. Gr. &?;; "y`dwr water + &?; fear: cf.
F. hydrophobie.] (Med.) (a) An abnormal dread of water, said to be a
symptom of canine madness; hence: (b) The disease caused by a bite
form, or inoculation with the saliva of, a rabid creature, of which the
chief symptoms are, a sense of dryness and construction in the throat,
causing difficulty in deglutition, and a marked heightening of reflex
excitability, producing convulsions whenever the patient attempts to
swallow, or is disturbed in any way, as by the sight or sound of water;
rabies; canine madness. [Written also hydrophoby.]
Hy`dro*phob"ic (?), a. [L. hydrophobicus, Gr. &?;: cf. F.
hydrophobique.] Of or pertaining to hydrophobia; producing or caused by
rabies; as, hydrophobic symptoms; the hydrophobic poison.
Hy"dro*pho`by (?), n. See Hydrophobia.
||Hy*droph"o*ra (?), n. pl. [NL., fr. E. hydra + Gr. &?; to bear.]
||(Zoˆl.) The Hydroidea.
Hy"dro*phore (?), n. [Gr. "y`dwr water + &?; to bear.] An instrument
used for the purpose of obtaining specimens of water from any desired
depth, as in a river, a lake, or the ocean.
||Hy`dro*phyl"li*um (?), n.; pl. L. Hydrophyllia (#), E. Hydrophylliums
||(#). [NL., fr. Gr. "y`dwr water + &?; a leaf.] (Zoˆl.) One of the
||flat, leaflike, protective zooids, covering other zooids of certain
||Siphonophora.
Hy"dro*phyte (?), n. [Gr. &?; + &?; plant: cf. F. hydrophyte.] An
aquatic plant; an alga.
Hy*droph`y*tol"o*gy (?), n. [Hydro- + phyte + -logy.] The branch of
botany which treats of water plants.
{ Hy*drop"ic (?), Hy*drop"ic*al (?), } a. [L. hydropicus, Gr. &?;: cf.
F. hydropique. See Dropsy.] Dropsical, or resembling dropsy.
Every lust is a kind of hydropic distemper, and the more we drink
the more we shall thirst.
Tillotson.
Hy*drop"ic*al*ly, adv. In a hydropical manner.
||Hy"dro*pi`per (?), n. [NL., fr. Gr. "y`dwr water + L. piper a
||pepper.] (Bot.) A species (Polygonum Hydropiper) of knotweed with
||acrid foliage; water pepper; smartweed.
Hy`dro*pneu*mat"ic (?), a. [Hydro- , 1 + pneumatic: cf. F.
hydropneumatique.] Pertaining to, or depending upon, both liquid and
gaseous substances; as, hydropneumatic apparatus for collecting gases
over water or other liquids.
Hy"drop`sy (?), n. Same as Dropsy.
Hy"dro*pult (?), n. [Hydro-, 1 + Gr. &?; to hurl.] A machine for
throwing water by hand power, as a garden engine, a fire extinguisher,
etc.
Hy`dro*qui"none (?), n. [Hydro-, 2 + quinone.] (Chem.) A white
crystalline substance, C6H4(OH)2, obtained by the reduction of quinone.
It is a diacid phenol, resembling, and metameric with, pyrocatechin and
resorcin. Called also dihydroxy benzene.
||Hy`dro*rhi"za (?), n.; pl. L. HydrorhizÊ (#), E. Hydrorhizas (#).
||[NL., fr. E. hydra + Gr. &?; a root.] (Zoˆl.) The rootstock or
||decumbent stem by which a hydroid is attached to other objects. See
||Illust. under Hydroidea.
Hy"dro*salt` (?), n. [Hydro-, 1 + salt.] (Chem.) (a) A salt supposed to
be formed by a hydracid and a base. (b) An acid salt. [R.] (c) A
hydrous salt; a salt combined with water of hydration or
crystallization.
<! p. 718 !>
Hy"dro*scope (?), n. [Hydro-, 1 + -scope.] 1. An instrument designed to
mark the presence of water, especially in air. Weale.
2. A kind of water clock, used anciently for measuring time, the water
tricking from an orifice at the end of a graduated tube.
{ Hy"dro*some (?), ||Hy`dro*so"ma (?) }, n. [NL. hydrosoma. See Hydra,
and -some body.] (Zoˆl.) All the zooids of a hydroid colony
collectively, including the nutritive and reproductive zooids, and
often other kinds.
Hy`dro*sor"bic (?), a. [Hydro-, 2 + sorbic.] (Chem.) Pertaining to, or
designating, an acid obtained from sorbic acid when this takes up
hydrogen; as, hydrosorbic acid.
Hy"dro*stat (?), n. A contrivance or apparatus to prevent the explosion
of steam boilers.
{ Hy`dro*stat"ic (?), Hy`dro*stat"ic*al (?), } a. [Hydro-, 1 + Gr. &?;
causing to stand: cf. F. hydrostatique. See Static.] Of or relating to
hydrostatics; pertaining to, or in accordance with, the principles of
the equilibrium of fluids.
The first discovery made in hydrostatics since the time of
Archimedes is due to Stevinus.
Hallam.
Hydrostatic balance, a balance for weighing substances in water, for
the purpose of ascertaining their specific gravities. -- Hydrostatic
bed, a water bed. -- Hydrostatic bellows, an apparatus consisting of a
water-tight bellowslike case with a long, upright tube, into which
water may be poured to illustrate the hydrostatic paradox. --
Hydrostatic paradox, the proposition in hydrostatics that any quantity
of water, however small, may be made to counterbalance any weight,
however great; or the law of the equality of pressure of fluids in all
directions. -- Hydrostatic press, a machine in which great force, with
slow motion, is communicated to a large plunger by means of water
forced into the cylinder in which it moves, by a forcing pump of small
diameter, to which the power is applied, the principle involved being
the same as in the hydrostatic bellows. Also called hydraulic press,
and Bramah press. In the illustration, a is a pump with a small plunger
b, which forces the water into the cylinder c, thus driving upward the
large plunder d, which performs the reduced work, such as compressing
cotton bales, etc.
Hy`dro*stat"ic*al*ly, adv. According to hydrostatics, or to hydrostatic
principles. Bentley.
Hy`dro*sta*ti"cian (?), n. One who is versed or skilled in
hydrostatics. [R.]
Hy`dro*stat"ics (?), n. [Cf. F. hydrostatique.] (Physics) The branch of
science which relates to the pressure and equilibrium of nonelastic
fluids, as water, mercury, etc.; the principles of statics applied to
water and other liquids.
Hy`dro*sul"phate (?), n. (Chem.) Same as Hydrosulphurent.
Hy`dro*sul"phide (?), n. (Chem.) One of a series of compounds, derived
from hydrogen sulphide by the replacement of half its hydrogen by a
base or basic radical; as, potassium hydrosulphide, KSH. The
hydrosulphides are analogous to the hydrates and include the
mercaptans.
Hy`dro*sul"phite (?), n. (Chem.) A saline compound of hydrosulphurous
acid and a base. [R.]