< 230 ) XXIV. GYPSUM FAMILY. Tins Family contains the following species: Gypsum, Anhydrite, Vulpinite, and Glauberite. I. Gypsum *. Gyps, Werner. '' This species is divided into five subspecies, viz. Earthy Gypsum, Compact Gypsum, Fibrous Gypsum, Foliated Gypsum, and Sparry Gypsum or Selenite. First * Ovp3um is from the Greek word Ftrpsg. The following explanation of the term yv^psg, shews that it was applied by the ancients to an earthy substance that had been exposed to the action of fire : Vv^tg clout yht'lc; rig ovfiz' a Z'^n&errct yr, (a): in which it corresjHjnds with the gypsum of the moderns. The ancient naturalists sometimes seem to upply the term to sulphate of lime, the gypsum of the present day, and sometimes to a calcined carbonate of lime, or quicklime, which they called cahc. In the following passage, it is applied to a sulphate of lime: “ Cognata calci res gypsum es«. Qui coquitur lapis non dissimilis alabastrit* esse delict: omnia autem optimum fieri compertum est e lapide spcculari, squnmainvc talem habente (4) the term lapis specularis applying very closely to our selenite, which is a “ulphate of lime. “ Gypsoma dicto stalim ulendum est, quotiiam celtrrime coit (r)the word cclerrime being more applicable to the comparatively rapid consolidation of calcined gypsum than to that <*t common mortar. There is a passage in Theophrastus, in which a ship » said to have been set on fire, in consequence of the moistening of its cargo- which consisted of gypsum and wcaring-apparel: in this case, there can b« little doubt, that the substance called gypsum could not have been of the same nature with the gypsum of the present day, which in no instance. I**' haps, contains such a proportion of carbonate of lime, as when cal«in« • would be sufficient to produce this effect.—KiiT» Min. vol. i. p. 69, TO, • ’ (a) Vid. Etymolog. Magn. (4) riin. Hist. Nat. lib. xxxvi. (<•) Pirn. Hist. Nat. Ub. xxxvi.