Hy`a*cin"thine (?), a. [L. hyacinthinus, Gr. &?;.] Belonging to the
hyacinth; resembling the hyacinth; in color like the hyacinth. Milton.
His curling locks like hyacinthine flowers.
Cowper.
The hyacinthine boy, for whom Morn well might break and April
bloom.
Emerson.
{ Hy"a*des (?), Hy"ads (?), } n. pl. [L. Hyades, Gr. &?;.] (Astron.) A
cluster of five stars in the face of the constellation Taurus, supposed
by the ancients to indicate the coming of rainy weather when they rose
with the sun.
Thro' scudding drifts the rainy Hyades Vext the dim sea.
Tennyson.
Hy*Ê"na (?), n. (Zoˆl.) Same as Hyena.
||Hy*a"le*a (?), n. [NL., fr. Gr. &?; glassy, fr. "y`alos glass.]
||(Zoˆl.) A pteropod of the genus Cavolina. See Pteropoda, and
||Illustration in Appendix.
Hy`a*les"cence (?), n. [See Hyaline.] The process of becoming, or the
state of being, transparent like glass.
Hy"a*line (?), a. [L. hyalinus, Gr. &?;, fr. "y`alos glass: cf. F.
hyalin.] Glassy; resembling glass; consisting of glass; transparent,
like crystal. "Hyaline spaces." Carpenter.
Hy"a*line, n. 1. A poetic term for the sea or the atmosphere. "The
clear hyaline, the glassy sea." Milton.
Our blood runs amazed 'neath the calm hyaline.
Mrs. Browning.
2. (Biol.) The pellucid substance, present in cells in process of
development, from which, according to some embryologists, the cell
nucleus originates.
3. (Physiol. Chem.) The main constituent of the walls of hydatid cysts;
a nitrogenous body, which, by decomposition, yields a dextrogyrate
sugar, susceptible of alcoholic fermentation. Gamgee.
Hy"a*lite (?), n. [Gr. "y`alos glass: cf. F. hyalite.] (Min.) A
pellucid variety of opal in globules looking like colorless gum or
resin; -- called also M¸ller's glass.
Hy*al"o*graph (?), n. [Gr. "y`alos glass + graph.] An instrument for
tracing designs on glass.
Hy`a*log"ra*phy (?), n. Art of writing or engraving on glass.
Hy"a*loid (?), a. [Gr. &?; glassy, transparent; "y`alos glass + &?;
appearance: cf. F. hyaloÔde.] (Anat.) Resembling glass; vitriform;
transparent; hyaline; as, the hyaloid membrane, a very delicate
membrane inclosing the vitreous humor of the eye.
||Hy`a*lo*ne"ma (?), n. [NL., fr. Gr. "y`alos glass + &?; a thread.]
||(Zoˆl.) A genus of hexactinelline sponges, having a long stem
||composed of very long, slender, transparent, siliceous fibres twisted
||together like the strands of a color. The stem of the Japanese
||species (H. Sieboldii), called glass-rope, has long been in use as an
||ornament. See Glass-rope.
Hy*al"o*phane (?), n. [Gr. "y`alos glass + &?; to appear.] (Min.) A
species of the feldspar group containing barium. See Feldspar.
||Hy`a*lo*spon"gi*a (?), n. pl. [NL., fr. Gr. "y`alos glass + &?; a
||sponge.] (Zoˆl.) An order of vitreous sponges, having glassy
||six-rayed, siliceous spicules; -- called also HexactinellinÊ.
Hy*al"o*type (?), n. [Gr. "y`alos glass + -type.] A photographic
picture copied from the negative on glass; a photographic transparency.
R. Hunt.
{ Hy*ber"na*cle (?), Hy"ber*nate (?), Hy`ber*na"tion (?). } See
Hibernacle, Hibernate, Hibernation.
Hy*blÊ"an (?), a. [L. Hyblaeus.] Pertaining to Hybla, an ancient town
of Sicily, famous for its bees.
Hyb"o*dont (?), a. [Gr. &?; hump + &?;, &?;, a tooth.] (Paleon.) Of,
pertaining to, or resembling, an extinct genus of sharks (Hybodus),
especially in the form of the teeth, which consist of a principal
median cone with smaller lateral ones.
||Hyb"o*dus (?), n. [NL. See Hybodont.] (Paleon.) An extinct genus of
||sharks having conical, compressed teeth.
Hy"brid (?), n. [L. hybrida, hibrida, prob. allied to Gr. &?;
wantonness (as if unbridled, lawless, unnatural), perh. akin to Gr.
"ype`r over, E. over: cf. F. hybride.] (Biol.) The offspring of the
union of two distinct species; an animal or plant produced from the
mixture of two species. See Mongrel.
Hy"brid, a. Produced from the mixture of two species; as, plants of
hybrid nature.
Hy"brid*ism (?), n. The state or quality of being hybrid.
Hy"brid*ist, n. One who hybridizes.
Hy*brid"i*ty (?), n. Hybridism.
Hy"brid*i`za*ble (?), a. Capable of forming a hybrid, or of being
subjected to a hybridizing process; capable of producing a hybrid by
union with another species or stock.
Hybridizable genera are rarer than is generally supposed, even in
gardens where they are so often operated upon, under circumstances
most favorable to the production of hybrids.
J. D. Hooker.
Hy`brid*i*za"tion (?), n. The act of hybridizing, or the state of being
hybridized.
Hy"brid*i`ze (?), v. t. [imp. & p. p. Hybridized (?); p. pr. & vb. n.
Hybridizing (?).] To render hybrid; to produce by mixture of stocks.
Hy"brid*i`zer (?), n. One who hybridizes.
Hy"brid*ous (?), a. Same as Hybrid.
Hyd"age (?), n. (Law) A land tax. See Hidage.
Hy`dan*to"ic (?), a. (Chem.) Pertaining to, or derived from, hydantoin.
See Glycoluric.
Hy*dan"to*in (?), n. [Hydrogen + allantion.] (Chem.) A derivative of
urea, C3H4N2O2, obtained from allantion, as a white, crystalline
substance, with a sweetish taste; -- called also glycolyl urea.
Hy"da*tid (?), n. [Gr. &?;, &?;, a watery vesicle under the upper
eyelid, fr. "y`dwr, "y`datos, water: cf. F. hydatide.] (Zoˆl.) A
membranous sac or bladder filled with a pellucid fluid, found in
various parts of the bodies of animals, but unconnected with the
tissues. It is usually formed by parasitic worms, esp. by larval
tapeworms, as Echinococcus and Cúnurus. See these words in the
Vocabulary.
Hydatid of Morgagni (Anat.), one of the small pedunculated bodies found
between the testicle and the head of the epididymis, and supposed to be
a remnant of the M¸llerian duct.
Hy*dat"i*form (?), a. [Hydatid + -form.] Resembling a hydatid.
Hy"da*toid (?), a. [Gr. "y`dwr, "y`datos, water + -oid.] (Anat.)
Resembling water; watery; aqueous; hyaloid.
Hy"dr- (?). See under Hydro-.
Hy"dra (?), n.; pl. E. Hydras (#), L. HydrÊ (#). [L. hydra, Gr. "y`dra;
akin to "y`dwr water. See Otter the animal, Water.] 1. (Class. Myth.) A
serpent or monster in the lake or marsh of Lerna, in the Peloponnesus,
represented as having many heads, one of which, when cut off, was
immediately succeeded by two others, unless the wound was cauterized.
It was slain by Hercules. Hence, a terrible monster.
Gorgons, and Hydras, and Chimeras dire.
Milton.
2. Hence: A multifarious evil, or an evil having many sources; not to
be overcome by a single effort.
3. (Zoˆl.) Any small fresh-water hydroid of the genus Hydra, usually
found attached to sticks, stones, etc., by a basal sucker.
The body is a simple tube, having a mouth at one extremity, surrounded
by a circle of tentacles with which it captures its prey. Young hydras
bud out from the sides of the older ones, but soon become detached and
are then like their parent. Hydras are remarkable for their power of
repairing injuries; for if the body be divided in pieces, each piece
will grow into a complete hydra, to which fact the name alludes. The
zooids or hydranths of marine hydroids are sometimes called hydras.
4. (Astron.) A southern constellation of great length lying southerly
from Cancer, Leo, and Virgo.
Hy*drach"nid (?), n. [Hydr- + arachnid.] (Zoˆl.) An aquatic mite of the
genus Hydrachna. The hydrachnids, while young, are parasitic on
fresh-water mussels.
Hy*drac"id (?), n. [Hydr- + acid: cf. F. hydracide.] (Chem.) An acid
containing hydrogen; -- sometimes applied to distinguish acids like
hydrochloric, hydrofluoric, and the like, which contain no oxygen, from
the oxygen acids or oxacids. See Acid.
Hy`dra*cryl"ic (?), a. [Hydr- + acrylic.] (Chem.) Pertaining to, or
designating, an isomeric variety of lactic acid that breaks down into
acrylic acid and water.
Hy`drac*tin"i*an (?), n. [See Hydra, and Actinia.] (Zoˆl.) Any species
or marine hydroids, of the genus Hydractinia and allied genera. These
hydroids form, by their rootstalks, a firm, chitinous coating on shells
and stones, and esp. on spiral shells occupied by hermit crabs. See
Illust. of Athecata.
<! p. 716 !>
||Hy*drÊ"mi*a (h*dr"m*), n. [NL., fr. Gr. "y`dwr water + a"i^ma blood.]
||(Med.) An abnormally watery state of the blood; anÊmia.
Hy"dra*gogue (?), a. [L. hydragogus conveying off water, Gr. &?;;
"y`dwr water + &?; to lead: cf. F. hydragogue.] (Med.) Causing a
discharge of water; expelling serum effused into any part of the body,
as in dropsy. -- n. A hydragogue medicine, usually a cathartic or
diuretic.
Hy*dram"ide (?), n. [Hydr- + -amide.] (Chem.) One of a group of
crystalline bodies produced by the action of ammonia on certain
aldehydes.
Hy*dram"ine (?), n. [Hydroxyl + amine.] (Chem.) One of a series of
artificial, organic bases, usually produced as thick viscous liquids by
the action of ammonia on ethylene oxide. They have the properties both
of alcohol and amines.
Hy*dran"ge*a (?), n. [NL., fr. Gr. "y`dwr water + &?; vessel, capsule:
cf. F. hydrangÈe.] (Bot.) A genus of shrubby plants bearing opposite
leaves and large heads of showy flowers, white, or of various colors.
H. hortensis, the common garden species, is a native of China or Japan.
Hy"drant (?), n. [Gr. &?; to irrigate, fr. "y`dwr water. See Hydra.] A
discharge pipe with a valve and spout at which water may be drawn from
the mains of waterworks; a water plug.
Hy"dranth (?), n. [Hydra + Gr. &?; a flower.] (Zoˆl.) One of the
nutritive zooids of a hydroid colony. Also applied to the proboscis or
manubrium of a hydroid medusa. See Illust. of Hydroidea.
Hy*drar"go*chlo"ride (?), n. [Hydrargyrum + chloride.] (Chem.) A
compound of the bichloride of mercury with another chloride. [Obs.]
Hy*drar"gy*rate (?), a. Of or pertaining to mercury; containing, or
impregnated with, mercury. [R.]
Hy*drar"gy*rism (?), n. (Med.) A diseased condition produced by
poisoning with hydrargyrum, or mercury; mercurialism.
Hy*drar"gy*rum (-rm), n. [NL., fr. L. hydrargyrus, Gr. "ydra`rgyros;
"y`dwr water + 'a`rgyros silver.] (Chem.) Quicksilver; mercury.
||Hy`drar*thro"sis (?), n. [NL. See Hydro-, 1, and Arthrosis.] (Med.)
||An effusion of watery liquid into the cavity of a joint.
Hy*dras"tine (?), n. (Chem.) An alkaloid, found in the rootstock of the
golden seal (Hydrastis Canadensis), and extracted as a bitter, white,
crystalline substance. It is used as a tonic and febrifuge.
Hy"dra-taint`ed (?), a. Dipped in the gall of the fabulous hydra;
poisonous; deadly. Cowper.
Hy"drate (?), n. [Gr. "y`dwr water: cf. F. hydrate.] (Chem.) (a) A
compound formed by the union of water with some other substance,
generally forming a neutral body, as certain crystallized salts. (b) A
substance which does not contain water as such, but has its
constituents (hydrogen, oxygen, hydroxyl) so arranged that water may be
eliminated; hence, a derivative of, or compound with, hydroxyl;
hydroxide; as, ethyl hydrate, or common alcohol; calcium hydrate, or
slaked lime.
Hy"drate (?), v. t. [imp. & p. p. Hydrated (?); p. pr. & vb. n.
Hydrating (?).] To form into a hydrate; to combine with water.
Hy"dra*ted (?), a. Formed into a hydrate; combined with water.
Hy*dra"tion (?), n. (Chem.) The act of becoming, or state of being, a
hydrate.
Water of hydration (Chem.), water chemically combined with some
substance to form a hydrate; -- distinguished from water of
crystallization.
Hy*drau"lic (?), a. [F. hydraulique, L. hydraulicus, fr. Gr. &?;, &?;,
a water organ; "y`dwr water + &?; flute, pipe. See Hydra.] Of or
pertaining to hydraulics, or to fluids in motion; conveying, or acting
by, water; as, an hydraulic clock, crane, or dock.
Hydraulic accumulator, an accumulator for hydraulic machinery of any
kind. See Accumulator, 2. -- Hydraulic brake, a cataract. See Cataract,
3. -- Hydraulic cement, a cement or mortar made of hydraulic lime,
which will harden under water. -- Hydraulic elevator, a lift operated
by the weight or pressure of water. -- Hydraulic jack. See under Jack.
-- Hydraulic lime, quicklime obtained from hydraulic limestone, and
used for cementing under water, etc. -- Hydraulic limestone, a
limestone which contains some clay, and which yields a quicklime that
will set, or form a firm, strong mass, under water. -- Hydraulic main
(Gas Works), a horizontal pipe containing water at the bottom into
which the ends of the pipes from the retorts dip, for passing the gas
through water in order to remove ammonia. -- Hydraulic mining, a system
of mining in which the force of a jet of water is used to wash down a
bank of gold-bearing gravel or earth. [Pacific Coast] -- Hydraulic
press, a hydrostatic press. See under Hydrostatic. -- Hydraulic
propeller, a device for propelling ships by means of a stream of water
ejected under water rearward from the ship. -- Hydraulic ram, a machine
for raising water by means of the energy of the moving water of which a
portion is to be raised. When the rush of water through the main pipe d
shuts the valve at a, the momentum of the current thus suddenly checked
forces part of it into the air chamber b, and up the pipe c, its return
being prevented by a valve at the entrance to the air chamber, while
the dropping of the valve a by its own weight allows another rush
through the main pipe, and so on alternately. -- Hydraulic valve.
(Mach.) (a) A valve for regulating the distribution of water in the
cylinders of hydraulic elevators, cranes, etc. (b) (Gas Works) An
inverted cup with a partition dipping into water, for opening or
closing communication between two gas mains, the open ends of which
protrude about the water.
Hy*drau"lic*al (?), a. Hydraulic.
Hy*drau"li*con (?), n. [NL. See Hydraulic.] (Mus.) An ancient musical
instrument played by the action of water; a water organ. [Written also
hydraulis.]
Hy*drau"lics (?), n. [Cf. F. hydraulique.] That branch of science, or
of engineering, which treats of fluids in motion, especially of water,
its action in rivers and canals, the works and machinery for conducting
or raising it, its use as a prime mover, and the like.
As a science, hydraulics includes hydrodynamics, or the principles of
mechanics applicable to the motion of water; as a branch of
engineering, it consists in the practical application of the mechanics
of fluids to the control and management of water with reference to the
wants of man, including canals, waterworks, hydraulic machines, pumps,
water wheels, etc. Some writers treat hydraulics and hydrostatics as
subdivisions of hydrodynamics.
Hy"dra*zine (?), n. [Hydr- + azo- + -ine.] (Chem.) Any one of a series
of nitrogenous bases, resembling the amines and produced by the
reduction of certain nitroso and diazo compounds; as, methyl hydrazine,
phenyl hydrazine, etc. They are derivatives of hydrazine proper,
H2N.NH2, which is a doubled amido group, recently (1887) isolated as a
stable, colorless gas, with a peculiar, irritating odor. As a base it
forms distinct salts. Called also diamide, amidogen, (or more properly
diamidogen), etc.
Hy"dren*ceph"s*loid (?), a. [Hydrencephalus + -oid.] (Med.) Same as
Hydrocephaloid.
||Hy"dri*a (?), n. [L., fr. Gr. &?;.] (Gr. Antiq.) A water jar; esp.,
||one with a large rounded body, a small neck, and three handles. Some
||of the most beautiful Greek vases are of this form.
Hy"dri*ad (?), n. [Gr. &?;, &?;, of the water, fr. "y`dwr water.]
(Myth.) A water nymph.
Hy"dric (?), a. [From Hydrogen.] (Chem.) Pertaining to, or containing,
hydrogen; as, hydric oxide.
Hydric dioxide. (Chem.) See Hydrogen dioxide, under Hydrogen. -- Hydric
oxide (Chem.), water. -- Hydric sulphate (Chem.), hydrogen sulphate or
sulphuric acid.
Hy"dride (?), n. [Hydr- + ide.] (Chem.) A compound of the binary type,
in which hydrogen is united with some other element.
Hy"dri*form (?), a. [Hydra + -form.] (Zoˆl.) Having the form or
structure of a hydra.
||Hy*dri"na (?), n. pl. [NL. See Hydra.] (Zoˆl.) The group of hydroids
||to which the fresh-water hydras belong.
Hy*dri"o*date (?), n. [Cf. F. hydriodate.] (Zoˆl.) Same as Hydriodide.
Hy`dri*od"ic (?), a. [Hydr- + iodic: cf. F. hydriodique.] (Chem.)
Pertaining to, or derived from, hydrogen and iodine; -- said of an acid
produced by the combination of these elements.
Hydriodic acid (Chem.), a pungent, colorless gas, HI, usually prepared
as a solution in water. It is strong reducing agent. Called also
hydrogen iodide.
Hy*dri"o*dide (?), n. (Chem.) A compound of hydriodic acid with a base;
-- distinguished from an iodide, in which only the iodine combines with
the base.
{ Hy"dro- (?), Hy"dr-. } 1. A combining form from Gr. &?;, &?;, water
(see Hydra).
2. (Chem.) A combining form of hydrogen, indicating hydrogen as an
ingredient, as hydrochloric; or a reduction product obtained by
hydrogen, as hydroquinone.
Hy`dro*ba*rom"e*ter (?), n. [Hydro- , 1 + barometer.] An instrument for
determining the depth of the sea water by its pressure.
Hy`dro*bil`i*ru"bin (?), n. [Hydro- , 2 + bilirubin.] (Physiol. Chem.)
A body formed from bilirubin, identical with urobilin.
||Hy`dro*bran`chi*a"ta (?), n. pl. [NL., fr. Gr. "y`dwr water + &?;
||gills.] (Zoˆl.) An extensive artificial division of gastropod
||mollusks, including those that breathe by gills, as contrasted with
||the Pulmonifera. -- Hy`dro*bran"chi*ate (#), a.
Hy`dro*bro"mate (?), n. (Chem.) Same as Hydrobromide.
Hy`dro*bro"mic (?), a. [Hydro-, 2 + bromic.] (Chem.) Composed of
hydrogen and bromine; as, hydrobromic acid.
Hydrobromic acid (Chem.), a colorless, pungent, corrosive gas, HBr,
usually collected as a solution in water. It resembles hydrochloric
acid, but is weaker and less stable. Called also hydrogen bromide.
Hy`dro*bro"mide (?), n. (Chem.) A compound of hydrobromic acid with a
base; -- distinguished from a bromide, in which only the bromine unites
with the base.
Hy`dro*car"bon (?), n. [Hydro-, 2 + carbon.] (Chem.) A compound
containing only hydrogen and carbon, as methane, benzene, etc.; also,
by extension, any of their derivatives.
Hydrocarbon burner, furnace, stove, a burner, furnace, or stove with
which liquid fuel, as petroleum, is used.
Hy`dro*car`bo*na"ceous (?), a. Of the nature, or containing,
hydrocarbons.
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.
Hy`dro*fer`ro*cy*an"ic (?), a. [Hydro-, 2 + ferrocyanic.] (Chem.)
Pertaining to, or containing, or obtained from, hydrogen, ferrous iron,
and cyanogen; as, hydroferrocyanic acid. See Ferrocyanic.
Hy`dro*flu"ate (?), n. (Chem.) A supposed compound of hydrofluoris acid
and a base; a fluoride. [Archaic]
Hy`dro*flu*or"ic (?), a. [Hydro- , 2 + fluoric.] (Chem.) Pertaining to,
or containing, hydrogen and fluorine; fluohydric; as, hydrofluoric
acid.
Hydrofluoric acid (Chem.), a colorless, mobile, volatile liquid, HF,
very corrosive in its action, and having a strong, pungent, suffocating
odor. It is produced by the action of sulphuric acid on fluorite, and
is usually collected as a solution in water. It attacks all silicates,
as glass or porcelain, is the agent employed in etching glass, and is
preserved only in vessels of platinum, lead, caoutchouc, or
gutta-percha.
<! p. 717 !>
Hy`dro*flu`o*sil"i*cate (?), n. (Chem.) A salt of hydrofluosilic acid;
a silicofluoride. See Silicofluoride.
Hy`dro*flu`o*si*lic"ic (?), a. [Hydro-, 2 + fluorine + silicic.]
(Chem.) Pertaining to, or denoting, a compound consisting of a double
fluoride of hydrogen and silicon; silicofluoric. See Silicofluoric.
Hy`dro*gal*van"ic (?), a. [Hydro- , 1 + galvanic.] Pertaining to,
produced by, or consisting of, electricity evolved by the action or use
of fluids; as, hydrogalvanic currents. [R.]
Hy"dro*gen (?), n. [Hydro-, 1 + -gen: cf. F. hydrogËne. So called
because water is generated by its combustion. See Hydra.] (Chem.) A
gaseous element, colorless, tasteless, and odorless, the lightest known
substance, being fourteen and a half times lighter than air (hence its
use in filling balloons), and over eleven thousand times lighter than
water. It is very abundant, being an ingredient of water and of many
other substances, especially those of animal or vegetable origin. It
may by produced in many ways, but is chiefly obtained by the action of
acids (as sulphuric) on metals, as zinc, iron, etc. It is very
inflammable, and is an ingredient of coal gas and water gas. It is
standard of chemical equivalents or combining weights, and also of
valence, being the typical monad. Symbol H. Atomic weight 1.
Although a gas, hydrogen is chemically similar to the metals in its
nature, having the properties of a weak base. It is, in all acids, the
base which is replaced by metals and basic radicals to form salts. Like
all other gases, it is condensed by great cold and pressure to a liquid
which freezes and solidifies by its own evaporation. It is absorbed in
large quantities by certain metals (esp. palladium), forming alloy-like
compounds; hence, in view of quasi-metallic nature, it is sometimes
called hydrogenium. It is the typical reducing agent, as opposed to
oxidizers, as oxygen, chlorine, etc.
Bicarbureted hydrogen, an old name for ethylene. -- Carbureted hydrogen
gas. See under Carbureted. -- Hydrogen dioxide, a thick, colorless
liquid, H2O2, resembling water, but having a bitter, sour taste,
produced by the action of acids on barium peroxide. It decomposes into
water and oxygen, and is manufactured in large quantities for an
oxidizing and bleaching agent. Called also oxygenated water. --
Hydrogen oxide, a chemical name for water, H&?;O. -- Hydrogen sulphide,
a colorless inflammable gas, H2S, having the characteristic odor of bad
eggs, and found in many mineral springs. It is produced by the action
of acids on metallic sulphides, and is an important chemical reagent.
Called also sulphureted hydrogen.
Hy"dro*gen*ate (?), v. t. [imp. & p. p. Hydrogenated (?); p. pr. & vb.
n. Hydrogenating (?).] (Chem.) To hydrogenize.
Hy`dro*gen*a"tion (?), n. (Chem.) The act of combining with hydrogen,
or the state of being so combined.
Hy"dro*gen*ide (?), n. (Chem.) A binary compound containing hydrogen; a
hydride. [R.] See Hydride.
Hy`dro*ge"ni*um (?), n. [NL. See Hydrogen.] (Chem.) Hydrogen; -- called
also in view of its supposed metallic nature. Graham.
Hy"dro*gen*ize (?), v. t. [imp. & p. p. Hydrogenized (?); p. pr. & vb.
n. Hydrogenizing (?).] (Chem.) To combine with hydrogen; to treat with,
or subject to the action of, hydrogen; to reduce; -- contrasted with
oxidize.
Hy*drog"e*nous (?), a. Of or pertaining to hydrogen; containing
hydrogen.
Hy*drog"no*sy (?), n. [Hydro-, 1 + Gr. &?; knowledge.] A treatise upon,
or a history and description of, the water of the earth.
Hy"drog*ode (?), n. [Hydrogen + Gr. &?; way. path.] (Elec.) The
negative pole or cathode. [R.]
Hy*drog"ra*pher (?), n. One skilled in the hydrography; one who
surveys, or draws maps or charts of, the sea, lakes, or other waters,
with the adjacent shores; one who describes the sea or other waters.
Boyle.
{ Hy`dro*graph"ic (?), Hy`dro*graph"ic*al (?), } a. Of or relating to
hydrography.
Hy*drog"ra*phy (?), n. [Hydro-, 1 + -graphy: cf. F. hydrographie.] 1.
The art of measuring and describing the sea, lakes, rivers, and other
waters, with their phenomena.
2. That branch of surveying which embraces the determination of the
contour of the bottom of a harbor or other sheet of water, the depth of
soundings, the position of channels and shoals, with the construction
of charts exhibiting these particulars.