Part 143

Hy"dro-a"ër*o*plane`. (Aëronautics) An aëroplane with a boatlike or other understructure that enables it to travel on, or to rise from the surface of, a body of water by its own motive power.

Hy"dro*bi"plane, n. A hydro- aëroplane having two supporting planes.

Hy*drol"y*sis (?), n. [Hydro-, 1 + -lysis.] (Chem.) A chemical process involving the addition of the elements of water.

Hy"dro*plane (?), n. [Pref. hydro- , 1 + plane.] 1. A plane, or any of a number of planes, projecting from the hull of a submarine boat, which by being elevated or depressed cause the boat, when going ahead, to sink or rise, after the manner of an aëroplane.

2. A projecting plane or fin on a gliding boat to lift the moving boat on top of the water; also, a gliding boat.

Hy"dro*plane, v. i. Of a boat, to plane (see Plane, below).

Hy`dro*pneu*mat"ic gun carriage. (Ordnance) A disappearing gun carriage in which the recoil is checked by cylinders containing liquid and air, the air when compressed furnishing the power for restoring the gun to the firing position. It is used with some English and European heavy guns.

Hy"dro*sphere (?), n. [Pref. hydro- , 1 + sphere.] 1. (Meteor.) The aqueous vapor of the entire atmosphere.

2. (Phys. Geog.) The aqueous envelope of the earth, including the ocean, all lakes, streams, and underground waters, and the aqueous vapor in the atmosphere.

Hy"dro*stat, n. A device, usually electrical, for indicating or regulating the height of water in a reservoir or receptacle.

Hy`dro*ther`a*peu"tics (?), n. [Hydro-, 1 + therapeutics.] (Med.) A system of treating disease by baths and mineral waters.

Hy*drot"ro*pism, n. (Bot.) In a broader sense, any curvature or turning induced in certain growing plant organs under the influence of moisture.

When the movement is toward the moisture, as is the case in most roots, the phenomenon is called positive hydrotropism; when away from the moisture, as in the case of hyphae of certain fungi, negative hydrotropism.

Hy`e*tol"o*gy (?), n. [Gr. &?; + rain -logy.] The science which treats of the precipitation of rain, snow, etc. -- Hy`e*to*log"ic*al (&?;), a.

Hyk"sos (?), n. [Gr. &?;, fr. Egypt. hikshasu chiefs of the Bedouins, shepherds.] A dynasty of Egyptian kings, often called the Shepherd kings, of foreign origin, who, according to the narrative of Manetho, ruled for about 500 years, forming the XVth and XVIth dynasties. It is now considered that the XVIth is merely a double of the XVth dynasty, and that the total period of the six Hyksos kings was little more than 100 years. It is supposed that they were Asiatic Semites.

Hyp`al*le"lo*morph, n. See Allelomorph.

Hyp"no*scope (?), n. [Gr. &?; + - scope.] (Physiol.) An instrument for ascertaining the susceptibility of a person to hypnotic influences.

||Hyp*no"sis, n. The condition of being hypnotized.

Hys`ter*et"ic (?), a. (Elec.) Of or pert. to hysteresis. -- Hysteretic constant, the hysteretic loss in ergs per cubic centimeter per cycle.

Ib"sen*ism (?), n. The dramatic practice or purpose characteristic of the writings of Henrik Ibsen (1828-1906), Norwegian poet and dramatist, whose best-known plays deal with conventional hypocrisies, the story in each play thus developing a definite moral problem.

Ich"thy*ol (?), n. [Gr. &?;, &?;, a fish + (prob.) L. oleum oil; but cf. Ichthyolite.] (Chem.) An oily substance prepared by the dry distillation of a bituminous mineral containing fossil fishes. It is used in medicine as a remedy in some forms of skin diseases.

I"con, n. (Gr. Ch.) A sacred picture representing the Virgin Mary, Christ, a saint, or a martyr, and having the same function as an image of such a person in the Latin Church.

I*con"o*graph (?), n. [See Iconography.] An engraving or other picture or illustration for a book.

I`co*no*ma"ni*a (?), n. [NL. See Icon, and Mania.] A mania or infatuation for icons, whether as objects of devotion, bric-a-brac, or curios.

I*de"al*ism, n. The practice or habit of giving or attributing ideal form or character to things; treatment of things in art or literature according to ideal standards or patterns; -- opposed to realism.

{ I*den"tic, I*den"tic*al }, a. In diplomacy (esp. in the form identic), precisely agreeing in sentiment or opinion and form or manner of expression; -- applied to concerted action or language which is used by two or more governments in treating with another government.

I"do ("d), n. An artificial international language, selected by the "Delegation for the Adoption of an Auxillary International Language" (founded at Paris in 1901), made public in 1907, and subsequently greatly revised and extended by a permanent committee or "Academy." It combines systematically the advantages of previous schemes with a thoroughly logical word formation, and has neither accented constants nor arbitrarily coined pronominal words. For each idea that root is selected which is already most international, on the principle of the "greatest facility for the greatest number of people." The word "Ido" means in the language itself "offspring." The official name is: "Linguo Internaciona di la Delegitaro (Sistema Ido)." -- I"dism (#), n. -- I"dist (#), n.

||I*do"lum (?), ||I*do"lon (&?;), n.; pl. Idola (#). [L. See Idol; cf. Eidolon.] Appearance or image; a phantasm; a spectral image; also, a mental image or idea.