Part 394

2. (Opt.) A polyscope, or multiplying glass.

Pol`y*he"drous (?), a. Polyhedral.

Pol`y*his"tor (?), n. [Gr. &?; very learned.] One versed in various learning. [R.]

Pol`y*hym"ni*a (?), n. [L., from Gr. &?;; poly`s many + &?; hymn.] (Anc. Myth.) The Muse of lyric poetry.

Pol`y*i"o*dide (?), n. (Chem.) A iodide having more than one atom of iodine in the molecule.

Po*lyl"o*gy (?), n. [Gr. &?;; poly`s much + &?; discourse.] Talkativeness. [R.]

Po*lyl"o*quent (?), a. [Poly- + L. loquens, p. pr. of logui to speak.] Garrulous; loquacious. [R.]

Pol`y*mas"tism (?), n. [Poly- + Gr. &?; a breast.] (Anat.) The condition of having more than two mammÊ, or breasts.

Pol`y*math"ic (?), a. [Cf. F. polymathique. See Polymathy.] Pertaining to polymathy; acquainted with many branches of learning.

Po*lym"a*thist (?), n. One versed in many sciences; a person of various learning.

Po*lym"a*thy (?), n. [Gr. &?;; poly`s much + &?;, &?;, to learn.] The knowledge of many arts and sciences; variety of learning. Johnson.

Pol`y*me*nis"cous (?), a. [See Poly- , and Meniscus.] (Zoˆl.) Having numerous facets; -- said of the compound eyes of insects and crustaceans.

Pol"y*mer (?), n. [See Polymeric.] (Chem.) Any one of two or more substances related to each other by polymerism; specifically, a substance produced from another substance by chemical polymerization. [Formerly also written polymere.]

Pol`y*mer"ic (?), a. [Poly- + Gr. &?; part.] (Chem.) Having the same percentage composition (that is, having the same elements united in the same proportion by weight), but different molecular weights; -- often used with with; thus, cyanic acid (CNOH), fulminic acid (C2N2O2H2), and cyanuric acid (C3N3O3H3), are polymeric with each other.

The figures expressing the number of atoms of each element in a number of polymeric substances are respectively multiples and factors of each other, or have some simple common divisor. The relation may be merely a numerical one, as in the example given above, or a chemical one, as in the case of aldehyde, paraldehyde, and metaldehyde.

Po*lym"er*ism (?), n. (Chem.) (a) The state, quality, or relation of two or more polymeric substances. (b) The act or process of forming polymers.

Pol`y*mer`i*za"tion (?), n. (Chem.) The act or process of changing to a polymeric form; the condition resulting from such change.

Pol"y*mer*ize (?), v. t. (Chem.) To cause polymerization of; to produce polymers from; to increase the molecular weight of, without changing the atomic proportions; thus, certain acids polymerize aldehyde.

Pol"y*mer*ize, v. i. (Chem.) To change into another substance having the same atomic proportions, but a higher molecular weight; to undergo polymerization; thus, aldehyde polymerizes in forming paraldehyde.

Po*lym"er*ous (?), a. 1. (Bot.) Having many parts or members in each set. Gray.

2. (Chem.) Polymeric. [Obs.]

Po*lym"ni*a (?), n. See Polyhymnia.

Pol"ym*nite (?), n. [Gr. &?; full of moss; poly`s much + &?; moss.] (Min.) A stone marked with dendrites and black lines, and so disposed as to represent rivers, marshes, etc.

Pol"y*morph (?), n. [Gr. &?; multiform; poly`s many + &?; form: cf. F. polymorphe.] (Crystallog.) A substance capable of crystallizing in several distinct forms; also, any one of these forms. Cf. Allomorph.

Pol`y*mor"phic (?), a. Polymorphous.

Pol`y*mor"phism (?), n. 1. (Crystallog.) Same as Pleomorphism.

2. (Biol.) (a) The capability of assuming different forms; the capability of widely varying in form. (b) Existence in many forms; the coexistence, in the same locality, of two or more distinct forms independent of sex, not connected by intermediate gradations, but produced from common parents.

||Pol`y*mor*pho"sis (?), n. [NL. See Poly-, and Morphosis.] (Zoˆl.) The ||assumption of several structural forms without a corresponding ||difference in function; -- said of sponges, etc.