Origin and history of spiro-

"winding around a fixed point or center, arranged like the thread of a screw," 1550s, from French spiral (16c.), from Medieval Latin spiralis "winding around a fixed center, coiling" (mid-13c.), from Latin spira "a coil, fold, twist, spiral," from Greek speira "a winding, a coil (of a snake, etc.), a twist, a wreath, any coiled or wound object (a belt, a rope)," from PIE *sperieh-, from a base *sper- "to turn, twist, wind," but Beekes seems doubtful. Related: Spirally. Spiral galaxy is attested by 1870; earlier it was a spiral nebula (1846) before their nature was grasped.

A spiral nebula has been discovered in the Dog's Ear, so strange and complex, that there is nothing to which it can be likened except a scroll gradually unfolding, or the evolution of a gigantic shell. Some of those nebulae which formerly appeared as nearly circular masses, have now been descried to have numerous luminous filaments streaming out in every direction, and interwoven with streams of stars. [Thomas Dick, LL.D., "The Christian Philosopher," 1846]