Part 258

{ Di`a*ther"man*cy (?), Di`a*ther`ma*ne"i*ty (?), } n. [See Diathermanous.] The property of transmitting radiant heat; the quality of being diathermous. Melloni.

Di`a*ther"ma*nism (?), n. The doctrine or the phenomena of the transmission of radiant heat. Nichol.

Di`a*ther"ma*nous (?), a. [Gr. &?; to warm through; dia` through + &?; to warm, &?; warm.] Having the property of transmitting radiant heat; diathermal; -- opposed to athermanous.

Di`a*ther"mic (?), a. Affording a free passage to heat; as, diathermic substances. Melloni.

Di`a*ther*mom"e*ter (?), n. [Gr. &?; warm + -meter. See Diathermal.] (Physics) An instrument for examining the thermal resistance or heat- conducting power of liquids.

Di`a*ther"mous (?), a. Same as Diathermal.

||Di*ath"e*sis (?), n. [NL., fr. Gr. &?;, fr. &?; to place separately, arrange; dia` through, asunder + &?; to place, put.] (Med.) Bodily condition or constitution, esp. a morbid habit which predisposes to a particular disease, or class of diseases.

Di`a*thet"ic (?), a. Pertaining to, or dependent on, a diathesis or special constitution of the body; as, diathetic disease.

Di"a*tom (d`*tm), n. [Gr. dia`tomos cut in two. See Diatomous.] 1. (Bot.) One of the Diatomaceæ, a family of minute unicellular Algæ having a siliceous covering of great delicacy, each individual multiplying by spontaneous division. By some authors diatoms are called Bacillariæ, but this word is not in general use.

2. A particle or atom endowed with the vital principle.

The individual is nothing. He is no more than the diatom, the bit of protoplasm.

Mrs. E. Lynn Linton.

Di`a*tom"ic (d`*tm"k), a. [Pref. di- + atomic.] (Chem.) (a) Containing two atoms. (b) Having two replaceable atoms or radicals.

Di*at"o*mous (?), a. [Gr. dia`tomos cut through, fr. diate`mnein to cut through; dia` through + te`mnein to cut. Cf. Diatom.] (Min.) Having a single, distinct, diagonal cleavage; -- said of crystals. Mohs.

Di`a*ton"ic (d`*tn"k), a. [L. diatonicus, diatonus, Gr. &?;, &?;, fr. &?; to stretch out; dia` through + &?; to stretch: cf. F. diatonique. See Tone.] (Mus.) Pertaining to the scale of eight tones, the eighth of which is the octave of the first.

Diatonic scale (Mus.), a scale consisting of eight sounds with seven intervals, of which two are semitones and five are whole tones; a modern major or minor scale, as distinguished from the chromatic scale.

Di`a*ton"ic*al*ly (?), adv. In a diatonic manner.

Di"a*tribe (?; 277), n. [L. diatriba a learned discussion, Gr. &?;, prop., a wearing away of time, fr. &?; to rub away, spend time; dia` through + &?; to rub: cf. L. terere, F. trite: cf. F. diatribe.] A prolonged or exhaustive discussion; especially, an acrimonious or invective harangue; a strain of abusive or railing language; a philippic.

The ephemeral diatribe of a faction.

John Morley.

Di*at"ri*bist (?), n. One who makes a diatribe or diatribes.

||Di`a*try"ma (?), n. [NL., from Gr. dia` through + &?; hole.] (Paleon.) An extinct eocene bird from New Mexico, larger than the ostrich.

{ Di`a*zeuc"tic (?), Di`a*zeu"tic (?), } a. [Gr. &?; disjunctive, fr. &?; to disjoin; dia` through, asunder + &?; to join, yoke.] (Anc. Mus.) Disjoining two fourths; as, the diazeutic tone, which, like that from F to G in modern music, lay between two fourths, and, being joined to either, made a fifth. [Obs.]

Di*az"o- (&?;). [Pref. di- + azo-] (Chem.) A combining form (also used adjectively), meaning pertaining to, or derived from, a series of compounds containing a radical of two nitrogen atoms, united usually to an aromatic radical; as, diazo-benzene, C6H5.N2.OH.

Diazo compounds are in general unstable, but are of great importance in recent organic chemistry. They are obtained by a partial reduction of the salts of certain amido compounds.

Diazo reactions (Chem.), a series of reactions whereby diazo compounds are employed in substitution. These reactions are of great importance in organic chemistry.

Di*az"o*tize (?), v. t. (Chem.) To subject to such reactions or processes that diazo compounds, or their derivatives, shall be produced by chemical exchange or substitution.

Dib (?), v. i. To dip. [Prov. Eng.] Walton.