rock-salt
[rock n.1]
Salt found in a free state disposed in strata, and capable of being extracted in large lumps.
| 1707 Lond. Gaz. No. 4385/3 The Antelope of..Leverpole, with Rock-Salt, taken the 12th Instant by two Privateers. 1748 Anson's Voy. ii. viii. 309 Some oakum, about a tun of rock salt, and between 30 and 40l. in specie. 1802 Playfair Huttonian Theory 364 The district..in Cheshire, which contains rock-salt, extends over a tract of fourteen or fifteen miles. 1853 Gregory Inorg. Chem. 98 Chlorine..occurs in prodigious quantity in the well-known substance, sea or rock-salt, in which it is combined with sodium. 1886 Winchell Walks Geol. Field 131 The sediments..would be deposited upon the bed of rock-salt. |
b. attrib. and Comb.
| 1708 Lond. Gaz. No. 4453/3 A Survey will be held at Topsham,..on Thursday the 5th of August, for a Rock Salt-house, with three Iron Pans. 1811 Trans. Geol. Soc. I. 38 The Cheshire Rock-Salt District. 1834–6 Encycl. Metrop. (1845) VIII. 430/2 Rock salt-pits are sunk at great expense. 1839 Ure Dict. Arts 1086 The great rock-salt formation of England occurs within the red marl. 1883 Science I. 518/2 Magnus found that rock-salt plates absorbed heat [etc.]. |