Webster’s Revised Unabridged Dictionary · 1913
Calx
Calx, n.; pl. E. Calxes (#), L. Calces (#). [L. Calx, calcis. limestone; cf. Gr. χάλιξ gravel. κρόκη, κροκάλη, pebble, Skr. çarkarā gravel, Ir. carraic rock Gael. carraig, W. careg, stone. Cf. Chalk.]
1. (Chem.) (a) Quicklime. [Obs.] (b) The substance which remains when a metal or mineral has been subjected to calcination or combustion by heat, and which is, or may be, reduced to a fine powder.
☞ Metallic calxes are now called oxides.
2. Broken and refuse glass, returned to the post.