Iridescent
(Ir`i*des"cent) a. [L. iris, iridis, the rainbow: cf. F. iridescent.] Having colors like the rainbow; exhibiting
a play of changeable colors; nacreous; prismatic; as, iridescent glass.
Iridian
(I*rid"i*an) a. Of or pertaining to the iris or rainbow.
Iridiated
(I*rid"i*a`ted) a. Iridescent.
Iridic
(I*rid"ic) a. Of or pertaining to the iris of the eye.
Iridic
(I*rid"ic), a. (Chem.) Of or pertaining to iridium; — said specifically of those compounds in which
iridium has a relatively high valence.
Iridioscope
(I*rid"i*o*scope) n. [See Iris, and -scope.] A kind of ophthalmoscope.
Iridious
(I*rid"i*ous) a. (Chem.) Of or pertaining to iridium; — applied specifically to compounds in
which iridium has a low valence.
Iridium
(I*rid"i*um) n. [NL., fr. L. iris, iridis, the rainbow. So called from the iridescence of some of its
solutions. See Iris.] (Chem.) A rare metallic element, of the same group as platinum, which it much
resembles, being silver-white, but harder, and brittle, and indifferent to most corrosive agents. With the
exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Symbol Ir. Atomic
weight 192.5.
Iridium usually occurs as a native alloy with osmium which may occur alone or with platinum. Iridium, as
an alloy with platinum, is used in bushing the vents of heavy ordnance. It is also used for the points of
gold pens, and in a finely powdered condition for painting porcelain black.
Iridize
(Ir"i*dize) v. t. [imp. & p. p. Iridized ; p. pr. & vb. n. Iridizing ]
1. To point or tip with iridium, as a gold pen.
2. To make iridescent; as, to iridize glass.
Iridoline
(I*rid"o*line) n. [Iridescent + L. oleum oil.] (Chem.) A nitrogenous base C10H9N, extracted
from coal-tar naphtha, as an oily liquid. It is a member of the quinoline series, and is probably identical
with lepidine.
Iridosmine
(Ir`i*dos"mine Ir`i*dos"mi*um) n. [Iridium + osmium.] (Min.) The native compound of iridium
and osmium. It is found in flattened metallic grains of extreme hardness, and is often used for pointing
gold pens.
Iris
(I"ris) n.; pl. E. Irises L. Irides [L. iris, iridis, the goddess, Gr. the rainbow, iris of the eye, the
plant Iris. Cf. Orris.]
1. (Class. Myth.) The goddess of the rainbow, and swift-footed messenger of the gods. Shak.
2. The rainbow. Sir T. Browne.
3. An appearance resembling the rainbow; a prismatic play of colors. Tennyson.
4. (Anat.) The contractile membrane perforated by the pupil, and forming the colored portion of the
eye. See Eye.
5. (Bot.) A genus of plants having showy flowers and bulbous or tuberous roots, of which the flower-
de- luce orris, and other species of flag are examples. See Illust. of Flower-de-luce.
6. (Her.) See Fleur-de-lis, 2.
