Part 5472

<hw>Hy*drog"u*ret</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[From <er>Hydrogen</er>.]</ety> <fld>(Chem.)</fld> <def>A hydride.</def> <mark>[Obs.]</mark>

<h1>Hydroid</h1> <Xpage=717>

<hw>Hy"droid</hw> <tt>(?)</tt>, <tt>a.</tt> <ety>[<ets>Hydra</ets> + -<ets>oid</ets>.]</ety> <fld>(Zo\'94l.)</fld> <def>Related to, or resembling, the hydra; of or pertaining to the Hydroidea.</def> -- <def2><tt>n.</tt> <def>One of the Hydroideas.</def></def2>

<h1>Hydroidea</h1> <Xpage=717>

<hw>Hy*droi"de*a</hw>, <tt>n. pl.</tt> <ety>[NL. See <er>Hydra</er>, and <er>-oid</er>.]</ety> <fld>(Zo\'94l.)</fld> <def>An extensive order of Hydrozoa or Acaleph\'91.</def> <altsp>[Written also <asp>Hydroida</asp>.]</altsp>

<note>&hand; This order includes the hydras and the free-swimming hydromedus\'91, together with a great variety of marine attached hydroids, many of which grow up into large, elegantly branched forms, consisting of a vast number of zooids (hydranths, gonophores, etc.), united by hollow stems. All the zooids of a colony are produced from one primary zooid, by successive buddings. The Siphonophora have also been included in this order by some writers. See <er>Gymnoblastea</er>, <er>Hydromedusa</er>, <er>Gonosome</er>, <er>Gonotheca</er>.</note>

<h1>Hydrokinetic</h1> <Xpage=717>

<hw>Hy`dro*ki*net"ic</hw> <tt>(?)</tt>, <tt>a.</tt> <ety>[<ets>Hydro-</ets>, 1 + <ets>kinetic</ets>.]</ety> <def>Of or pertaining to the motions of fluids, or the forces which produce or affect such motions; -- opposed to <i>hydrostatic</i>.</def>

<i>Sir W. Thomson.</i>

<h1>Hydrological</h1> <Xpage=717>

<hw>Hy`dro*log"ic*al</hw> <tt>(?)</tt>, <tt>a.</tt> <def>Of or pertaining to hydrology.</def>

<h1>Hydrologist</h1> <Xpage=717>

<hw>Hy*drol"o*gist</hw> <tt>(?)</tt>, <tt>n.</tt> <def>One skilled in hydrology.</def>

<h1>Hydrology</h1> <Xpage=717>

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

<h1>Hydrolytic</h1> <Xpage=717>

<hw>Hy`dro*lyt"ic</hw> <tt>(?)</tt>, <tt>a.</tt> <ety>[<ets>Hydro-</ets>, 1 + Gr. <?/ to loose.]</ety> <fld>(Chem.)</fld> <def>Tending to remove or separate water; eliminating water.</def>

<blockquote><b>Hydrolytic</b> agents, such as sulphuric acid or caustic alkali. <i>Encyc. Brit.</i></blockquote>

<cs><col>Hydrolitic ferment</col> <fld>(Physiol. Chem.)</fld>, <cd>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.</cd></cs><-- = hydrolase (after 1910) -->

<h1>Hydromagnesite</h1> <Xpage=717>

<hw>Hy`dro*mag"ne*site</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[<ets>Hydro-</ets>, 1 + <ets>magnesite</ets>.]</ety> <fld>(Min.)</fld> <def>A hydrous carbonate of magnesia occurring in white, early, amorphous masses.</def>

<h1>Hydromancy</h1> <Xpage=717>

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

<h1>Hydromantic</h1> <Xpage=717>

<hw>Hy`dro*man"tic</hw> <tt>(?)</tt>, <tt>a.</tt> <ety>[Cf. F. <ets>hydromantique</ets>.]</ety> <def>Of or pertaining to divination by water.</def>

<h1>Hydromechanics</h1> <Xpage=717>

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

<h1>Hydromedusa</h1> <Xpage=717>