"We live submerged at the bottom of an ocean of elementary air. . . ."

"Noi viviamo sommersi nel fondo d’un pelago d’aria elementare. . . ."

"We live submerged at the bottom of a sea of elementary air. . . ."

     Evangelista Torricelli, in a letter to Michelangelo Ricci dated 11 June 1644.  Opere di Evangelista Torricelli, ed. Gino Loria and Giuseppe Vassura, 3 vols. in 4, vol. 1.2 (Faenza:  G. Montanari, 1919), 472.

     Remember:  air was one of the four elements ("uno de'quattro elementi"), and "elementary" had first in English that sense, as in c. 1440, "God is not fyre elementare", or in 1652, "The whole Elementary air being of its owne nature most subtile" (OED).