▪ I. gypsum, n. Min.
(ˈdʒɪpsəm)
Pl. 8 gypsa, 8–9 gypsums.
[a. L. gypsum, ad. Gr. γύψος chalk, gypsum.]
Hydrous calcium sulphate, the mineral from which plaster of Paris is made.
| [1387 Trevisa Higden (Rolls) I. 271 Bysides Parys is greet plente of a manere stoon þat hatte gypsus.] 1646 Sir T. Browne Pseud. Ep. ii. v. 92 Gypsum layed up in the earth the space of 80 yeeres. 1662 Evelyn Chalcogr. (1769) 33 Figures in..gypsum. 1759 W. Cullen Let. in Life (1832) I. 127 Are the talcs and gypsums different in their Composition. 1776 Woulfe in Phil. Trans. LXVI. 610 The Bolognian stone and other such spars, as well as the gypsa, are decomposed by fixed alkalies. a 1817 T. Dwight Trav. New Eng. etc. (1821) II. 343 Lands, dressed with gypsum, have been equally favourable to wheat. 1860 Tyndall Glac. ii. xxxi. 409 The prism presented the appearance of a crystal of gypsum. 1871 Roscoe Elem. Chem. 218 Gypsum when moderately heated loses its water, and is then called plaster of Paris. |
| attrib. 1823 Buckland Reliq. Diluv. 169 Ancient and modern bones occur mixed together only in the gypsum cavities. 1849 Sk. Nat. Hist., Mammalia III. 95 The gypsum-quarries near Paris. 1862 Proc. Amer. Phil. Soc. IX. 33 These gypsum deposits have no geological connection with the coal. |
▪ II. gypsum, v.
(ˈdʒɪpsəm)
[f. gypsum n.]
trans. To dress (land or a crop) with gypsum.
| 1819 Commun. Board Agric. 521 The whole field..was again gypsumed at the rate of four bushels per acre. 1834 Brit. Husb. I. 323 Cattle show..a remarkable predilection for clover which has been gypsumed. |
Hence ˈgypsumed ppl. a.
| 1841 Jrnl. R. Agric. Soc. II. i. 111 The comparative produce of the gypsumed over not gypsumed land is very great. 1849 J. F. W. Johnston Exper. Agric. 120 On wheat, after gypsumed clover. |