HYDROCHLORIC, h[=i]-dro-kl[=o]'rik, _adj._ compounded of hydrogen and chlorine.--_n._ HYDROCHL[=O]'RATE, a salt of hydrochloric acid.
HYDROCYANIC, h[=i]-dro-s[=i]-an'ik, _adj._ noting an acid formed by the combination of hydrogen and cyanogen--also _Prussic acid_.--_ns._ HYDROCY'ANIDE, HYDROCY'ANITE.
HYDRODYNAMICS, h[=i]-dro-di-nam'iks, _n.pl._ used as _sing._, the science that treats of the motions and equilibrium of a material system partly or wholly fluid, called _Hydrostatics_ when the system is in equilibrium, _Hydrokinetics_ when it is not.--_adjs._ HYDRODYNAM'IC, -AL.--_n._ HYDRODYNAMOM'ETER, an instrument for measuring the velocity of fluid in motion by its pressure.--_adj._ HYDROELEC'TRIC, pertaining to electricity generated by the escape of steam under high pressure.--_n._ HY'DRO-EXTRACT'OR, an apparatus for removing moisture from yarns, cloths, &c., in process of manufacture. [Gr. _hyd[=o]r_, water, and _dynamics_.]
HYDROFLUORIC, h[=i]-dro-fl[=oo]-or'ik, _adj._ consisting of fluorine and hydrogen.
HYDROGEN, h[=i]'dro-jen, _n._ a gas which in combination with oxygen produces water, an elementary gaseous substance, the lightest of all known substances, and very inflammable.--_adjs._ HY'DRIC, containing hydrogen; HYDROG'ENOUS, containing hydrogen: produced by the action of water, as applied to rocks in opposition to those that are _pyrogenous_, formed by the action of fire. [A word coined by Cavendish (1766) from Gr. _hyd[=o]r_, water, and _gen[=e]s_, producing.]
HYDROGRAPHY, h[=i]-drog'ra-fi, _n._ the art of measuring and describing the size and position of waters or seas: the art of making sea-charts.--_n._ HYDROG'RAPHER, a maker of sea-charts.--_adjs._ HYDROGRAPH'IC, -AL.--_adv._ HYDROGRAPH'ICALLY. [Gr. _hyd[=o]r_, water, _graphein_, to write.]
HYDROKINETICS, h[=i]-dro-ki-net'iks, _n.pl._ used as _sing._, a branch of _Hydrodynamics_ (q.v.).
HYDROLOGY, h[=i]-drol'o-ji, _n._ the science which treats of water.--_adjs._ HYDROLOG'IC, -AL.--_n._ HYDROL'OGIST. [Gr. _hyd[=o]r_, water, _logia_, a discourse.]
HYDROLYSIS, h[=i]-drol'i-sis, _n._ a kind of chemical decomposition by which a compound is resolved into other compounds by taking up the elements of water.--_adj._ HYDROLYT'IC. [Gr. _hyd[=o]r_, water, _lysis_--_lyein_, to loose.]
HYDROMANCY, h[=i]'dro-man-si, _n._ divination by water.--_adj._ HYDROMANT'IC. [Gr. _hyd[=o]r_, water, _manteia_, divination.]
HYDROMANIA, h[=i]-dro-m[=a]'ni-a, _n._ an insatiable craving for water, as in diabetes: a morbid propensity to suicide by drowning.
HYDROMECHANICS, h[=i]-dro-me-kan'iks, _n._ the mechanics of fluids.
HYDROMEL, h[=i]'dro-mel, _n._ a beverage made of honey and water. [Gr.
_hyd[=o]r_, water, _meli_, honey.]
HYDROMETAMORPHISM, h[=i]-dro-met-a-mor'fizm, _n._ a kind of metamorphism of igneous rocks brought about by water, in opposition to _Pyrometamorphism_, that brought about by means of heat.
HYDROMETEOROLOGY, h[=i]-dro-m[=e]-te-or-ol'o-ji, _n._ the branch of meteorology which treats of water in the atmosphere, as rain, clouds, snow, &c.--_n._ HYDROM[=E]'TEOR, any one of the aqueous phenomena of the atmosphere. [Gr. _hyd[=o]r_, water, _mete[=o]ron_, a meteor.]
HYDROMETER, h[=i]-drom'et-[.e]r, _n._ an instrument for measuring the density or specific gravity of solids and liquids by flotation, consisting of a weighted glass bulb or hollow metal cylinder with a long stem: a current-gauge.--_adjs._ HYDROMET'RIC, -AL.--_n._ HYDROM'ETRY. [Gr.
_hyd[=o]r_, water, _metron_, a measure.]
HYDROMOTOR, h[=i]-dro-m[=o]'tor, _n._ a form of motor for propelling vessels by means of jets of water ejected from the sides or stern.
HYDROMYS, h[=i]'dro-mis, _n._ an Australasian genus of rodents, known as water-rats and beaver-rats. [Gr. _hyd[=o]r_, water, _mys_, mouse.]
HYDRONETTE, h[=i]'dro-net, _n._ a syringe: a garden force-pump.
HYDROPATHY, h[=i]-drop'a-thi, _n._ the treatment of disease by cold water.--_adjs._ HYDROPATH'IC, -AL.--_adv._ HYDROPATH'ICALLY.--_n._ HYDROP'ATHIST, one who practises hydropathy.--HYDROPATHIC ESTABLISHMENT or (_coll._) simply HYDROPATH'IC, a temperance hotel where the guests can have hydropathic treatment if desired. [Gr. _hyd[=o]r_, water, _pathos_, suffering, _pathein_, to suffer.]
HYDROPHANE, h[=i]'dro-f[=a]n, _n._ a partly translucent variety of opal which becomes transparent when wetted.--_adj._ HYDROPH'ANOUS. [Gr.
HYD[=O]R, water, _phainein_, to shine.]
HYDROPHIDae, h[=i]-drof'i-d[=e], _n.pl._ a family of venomous sea-snakes.
[Gr. _hyd[=o]r_, water, _ophis_, snake.]
HYDROPHOBIA, h[=i]-dro-f[=o]'bi-a, _n._ an unnatural dread of water, a symptom of a disease known as Rabies, usually resulting from the bite of a mad dog--hence the disease itself.--_adj._ HYDROPHOB'IC. [Gr. _hyd[=o]r_, water, _phobos_, fear.]
HYDROPHONE, h[=i]'dro-f[=o]n, _n._ a marine electric apparatus for detecting the approach of a torpedo-boat, &c.
HYDROPHORE, h[=i]'dro-f[=o]r, _n._ an apparatus for obtaining specimens of water from any required depth.
HYDROPHTHALMIA, h[=i]-drof-thal'mi-a, _n._ an increase in quantity of the aqueous or the vitreous humour.
HYDROPHYTE, h[=i]'dro-f[=i]t, _n._ a plant living in water.--_n._ HYDROPHYTOG'RAPHY, the branch of botany which describes such--also HYDROPHYTOL'OGY. [Gr. _hyd[=o]r_, water, _phyton_, a plant, _logia_, discourse.]
HYDROPSY, h[=i]'drop-si, _n._ dropsy.--_adjs._ HYDROP'IC, HYDROP'TIC, dropsical: thirsty.
HYDROPULT, h[=i]'dro-pult, _n._ a hand force-pump.
HYDROSAURUS, h[=i]-dro-saw'rus, _n._ a genus of monitor-lizards, of aquatic habit, found in the Malay Peninsula, &c. [Gr. _hyd[=o]r_, water, _sauros_, a lizard.]
HYDROSCOPE, h[=i]'dro-sk[=o]p, _n._ a kind of water-clock, consisting of a cylindrical graduated tube, from which the water escaped through a hole in the bottom. [Gr. _hyd[=o]r_, water, _skopein_, to view.]
HYDROSOMA, h[=i]-dro-s[=o]'ma, _n._ the entire organism of any hydrozoon:--_pl._ HYDROS[=O]'MATA.--_adjs._ HYDROS[=O]'MAL, HYDROS[=O]'MATOUS.
HYDROSTATICS, h[=i]-dro-stat'iks, _n.pl._ used as _sing._, a branch of HYDRODYNAMICS (which see).--_n._ HY'DROSTAT, an electrical contrivance for detecting a leakage or overflow of water: an apparatus devised to guard against the explosion of steam boilers.--_adjs._ HYDROSTAT'IC, -AL.--_adv._ HYDROSTAT'ICALLY.--HYDROSTATIC BALANCE, a balance for weighing bodies in water to determine their specific gravity; HYDROSTATIC BELLOWS, a device for illustrating the law that fluid pressure is proportional to area; HYDROSTATIC PARADOX, the principle that (disregarding molecular forces) any quantity of fluid, however small, may balance any weight, however great, as in the hydrostatic bellows; HYDROSTATIC PRESS, the same as Hydraulic Press.
HYDROSULPHURIC, h[=i]-dro-sul-f[=u]'rik, _adj._ formed by a combination of hydrogen and sulphur.
HYDROTELLURIC, h[=i]-dro-tel-l[=u]'rik, _adj._ pertaining to hydrogen and tellurium.
HYDRO-THERAPEUTICS, h[=i]-dro-ther-a-p[=u]'tiks, _n.pl._ remedial treatment of disease by water in various modes and forms--also HYDROTHER'APY.--_adj._ HYDROTHERAPEU'TIC.
HYDROTHERMAL, h[=i]-dro-ther'mal, _adj._ pertaining to, or produced by, action of heated or super-heated water, esp. in dissolving, transporting, and redepositing mineral matter.
HYDROTHORAX, h[=i]-dro-th[=o]'raks, _n._ a term applied to dropsical collections in the pleura. [Gr. _hyd[=o]r_, water, _th[=o]rax_, chest.]
HYDROTROPISM, h[=i]-dro-trop'izm, _n._ the habit induced in a growing organ by the influence of moisture, of turning toward, or away from, the moisture.--_adj._ HYDROTROP'IC. [Gr. _hyd[=o]r_, water, _tropos_, a turn.]
HYDROUS, h[=i]'drus, _adj._ watery, containing hydrogen.
HYDROXIDE, h[=i]-droks'[=i]d, _n._ a metallic or basic radical combined with one or more hydroxyl groups.--_n._ HYDROX'YL, a compound radical not yet isolated, but found in many chemical compounds.
HYDROZOA, h[=i]-dro-z[=o]'a, _n.pl._ (_sing._ HYDROZ[=O]'ON) one of the main divisions of the sub-kingdom _Coelenterata_, the other two being _Ctenophora_ and _Anthozoa_ or _Actinozoa_; they are chiefly marine organisms, soft and gelatinous, free or fixed, existing everywhere, endlessly varied in form and complexity of structure, including such great groups as _hydroids_, _acalephs_, _medusans_, jelly-fish, sea-blubbers, &c.--_adjs._ HYDROZ[=O]'AN, HYDROZ[=O]'IC. [Gr. _hyd[=o]r_, water, _z[=o]on_, an animal.]
HYDRURET. Same as HYDRID.
HYENA, h[=i]-[=e]'na, HYEN, h[=i]'en, _n._ (_Shak._) a hyaena.
HYETAL, h[=i]'e-tal, _adj._ rainy.--_n._ HY'ETOGRAPH, a chart showing the average rainfall of the earth or any of its divisions.--_adjs._ HYETOGRAPH'IC, -AL.--_ns._ HYETOG'RAPHY; HYETOL'OGY; HYETOM'ETER; HYETOMET'ROGRAPH. [Gr. _hyetos_, rain.]
HYGEIAN, h[=i]-j[=e]'an, _adj._ relating to health and its preservation.--_ns._ HYGEIA (h[=i]-j[=e]'a), goddess of health, daughter of aesculapius; HY'GI[=E]NE, HYGIEN'ICS, HY'GIENISM, the science which treats of the preservation of health.--_adj._ HYGIEN'IC.--_adv._ HYGIEN'ICALLY.--_n._ HY'GIENIST, one skilled in hygiene; HYGIOL'OGY, art of the preservation of health. [Gr. _hygieia_--_hygi[=e]s_, healthy.]
HYGRODEIK, h[=i]'gro-d[=i]k, _n._ a form of hygrometer in which the atmospheric humidity is indicated by an index controlled by the heights of a wet-bulb and a dry-bulb thermometer, supported on each side of a frame on which is described a scale. [Gr. _hygros_, wet, _deik-nynai_, to show.]
HYGROMETER, h[=i]-grom'et-[.e]r, _n._ an instrument for measuring the moisture in the atmosphere, or its relative humidity.--_n._ HYGROM'ETRY, the art of measuring the moisture in the atmosphere, and of bodies generally.--_adjs._ HYGROMET'RIC, -AL. [Gr. _hygros_, wet, _metron_, a measure.]