Part 953

Hy`dro*log"ic*al (?), a. Of or pertaining to hydrology.

Hy*drol"o*gist (?), n. One skilled in hydrology.

Hy*drol"o*gy (?), n. [Hydro-, 1 + -logy: cf. F. hydrologie.] The science of water, its properties, phenomena, and distribution over the earth's surface.

Hy`dro*lyt"ic (?), a. [Hydro-, 1 + Gr. &?; to loose.] (Chem.) Tending to remove or separate water; eliminating water.

Hydrolytic agents, such as sulphuric acid or caustic alkali.

Encyc. Brit.

Hydrolytic ferment (Physiol. Chem.), a ferment, enzyme, or chemical ferment, which acts only in the presence of water, and which causes the substance acted upon to take up a molecule of water. Thus, diastase of malt, ptyalin of saliva, and boiling dilute sulphuric acid all convert starch by hydration into dextrin and sugar. Nearly all of the digestive ferments are hydrolytic in their action.

Hy`dro*mag"ne*site (h`dr*mg"n*st), n. [Hydro-, 1 + magnesite.] (Min.) A hydrous carbonate of magnesia occurring in white, earthy, amorphous masses.

Hy"dro*man`cy (?), n. [Hydro-, 1 + -mancy: cf. F. hydromancie.] Divination by means of water, -- practiced by the ancients.

Hy`dro*man"tic (?), a. [Cf. F. hydromantique.] Of or pertaining to divination by water.

Hy`dro*me*chan"ics (?), n. [Hydro- , 1 + mechanics.] That branch of physics which treats of the mechanics of liquids, or of their laws of equilibrium and of motion.

||Hy`dro*me*du"sa (?), n.; pl. HydromedusÊ (#). [NL. See Hydra, and ||Medusa.] (Zoˆl.) Any medusa or jellyfish which is produced by budding ||from a hydroid. They are called also Craspedota, and naked-eyed ||medusÊ.

Such medusÊ are the reproductive zooids or gonophores, either male or female, of the hydroid from which they arise, whether they become free or remain attached to the hydroid colony. They in turn produce the eggs from which the hydroids are developed. The name is also applied to other similar medusÊ which are not known to bud from a hydroid colony, and even to some which are known to develop directly from the eggs, but which in structure agree essentially with those produced from hydroids. See Hydroidea, and Gymnoblastea.

Hy"dro*mel (?), n. [L. hydromel, hydromeli, Gr. &?;; &?; water + &?; honey: cf. F. hydromel.] A liquor consisting of honey diluted in water, and after fermentation called mead.

Hy`dro*mel*lon"ic (?), a. See Cyamellone.

Hy`dro*met`al*lur"gic*al (?), a. Of or pertaining to hydrometallurgy; involving the use of liquid reagents in the treatment or reduction of ores. -- Hy`dro*met`al*lur"gic*al*ly, adv.

Hy`dro*met"al*lur`gy (?), n. [Hydro- , 1 + metallurgy.] The art or process of assaying or reducing ores by means of liquid reagents.

Hy`dro*me"te*or (?), n. [Hydro-, 1 + meteor.] A meteor or atmospheric phenomenon dependent upon the vapor of water; -- in the pl., a general term for the whole aqueous phenomena of the atmosphere, as rain, snow, hail, etc. Nichol.

Hy`dro*me`te*or`o*log"ic*al (?), a. Of or pertaining to hydrometeorology, or to rain, clouds, storms, etc.

Hy`dro*me`te*or*ol"o*gy (?), n. [Hydro-, 1 + meteorology.] That branch of meteorology which relates to, or treats of, water in the atmosphere, or its phenomena, as rain, clouds, snow, hail, storms, etc.

Hy*drom"e*ter (?), n. [Hydro-, 1 + -meter: cf. F. hydromËtre.] 1. (Physics) An instrument for determining the specific gravities of liquids, and thence the strength spirituous liquors, saline solutions, etc.

It is usually made of glass with a graduated stem, and indicates the specific gravity of a liquid by the depth to which it sinks in it, the zero of the scale marking the depth to which it sinks in pure water. Extra weights are sometimes used to adapt the scale to liquids of different densities.

2. An instrument, variously constructed, used for measuring the velocity or discharge of water, as in rivers, from reservoirs, etc., and called by various specific names according to its construction or use, as tachometer, rheometer, hydrometer, pendulum, etc.; a current gauge.

{ Hy`dro*met"ric (?), Hy`dro*met"ric*al (?), } a. [Cf. F. hydromËtrique.] 1. Of or pertaining to an hydrometer, or to the determination of the specific gravity of fluids.

2. Of or pertaining to measurement of the velocity, discharge, etc., of running water.

3. Made by means of an hydrometer; as, hydrometric observations.

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.