He"li*um (?), n. [NL., fr. Gr. &?; the sun.] (Chem.) A gaseous element
found in the atmospheres of the sun and earth and in some rare
minerals.
<! p. 683 !>
He"lix (?), n.; pl. L. Helices (#), E. Helixes (#). [L. helix, Gr. &?;,
&?;, fr. &?; to turn round; cf. L. volvere, and E. volute, voluble.] 1.
(Geom.) A nonplane curve whose tangents are all equally inclined to a
given plane. The common helix is the curve formed by the thread of the
ordinary screw. It is distinguished from the spiral, all the
convolutions of which are in the plane.
2. (Arch.) A caulicule or little volute under the abacus of the
Corinthian capital.
3. (Anat.) The incurved margin or rim of the external ear. See Illust.
of Ear.