Defn: A white crystalline substance, C6H4(OH)2, obtained by the reduction of quinone. It is a diacid phenol, resembling, and metameric with, pyrocatechin and resorcin. Called also dihydroxy benzene.
HYDRORHIZA
Hy`dro*rhi"za, n.; pl. L. Hydrorhizæ, E. Hydrorhizas. Etym: [NL., fr.
E. hydra + Gr. (Zoöl.)
Defn: The rootstock or decumbent stem by which a hydroid is attached to other objects. See Illust. under Hydroidea.
HYDROSALT Hy"dro*salt`, n. Etym: [Hydro-, 1 + salt.] (Chem.) (a) A salt supposed to be formed by a hydracid and a base. (b) An acid salt. [R.] (c) A hydrous salt; a salt combined with water of hydration or crystallization.
HYDROSCOPE
Hy"dro*scope, n. Etym: [Hydro-, 1 + -scope.]
1. An instrument designed to mark the presence of water, especially in air. Weale.
2. A kind of water clock, used anciently for measuring time, the water tricking from an orifice at the end of a graduated tube.
HYDROSOME; HYDROSOMA Hy"dro*some, Hy`dro*so"ma, n. Etym: [NL. hydrosoma. See Hydra, and - some body.] (Zoöl.)
Defn: All the zooids of a hydroid colony collectively, including the nutritive and reproductive zooids, and often other kinds.
HYDROSORBIC
Hy`dro*sor"bic, a. Etym: [Hydro-, 2 + sorbic.] (Chem.)