| 释义 |
colcothar|ˈkɒlkəʊθa(r)|
Also 7 -chotar, -cotar, -kethor.
[So in F., Pg. and med.L. (also calcatar), Sp. colcotar, ad. Arab. qolqotār (Pedro de Alcalá, 1505), thought by Dozy to be a corruption of Gr. χάλκανθος or χαλκανθές chalcanth.]
The brownish red peroxide of iron which remains in the retort after the distillation of sulphuric acid from iron sulphate.
It is used in medicine, in the mechanical arts, and in a finely powdered form by jewellers under the name of rouge; also called Crocus Martis.
1605Timme Quersit. i. xiii. 53 The colchotar, or red feces which remayneth in the bottome. 1646Sir T. Browne Pseud. Ep. vi. xii. 337 Colcothar or vitriol burnt, though unto a rednesse containing the fixed salt, will make good Inke. 1791E. Darwin Bot. Gard. i. Notes 52 The precipitates of gold, and the colcothar of other red preparations of iron, are called tender colours. 1799G. Smith Laborat. I. 95 Take red calcined vitriol, or colcothar of vitriol. 1832G. Porter Porcelain & Gl. 209 The previously polished side is provided with a coating of red colcothar.
b. Formerly applied to analogous compounds of other metals.
1612Woodall Surg. Mate Wks. (1653) 216 This Colkethor is of two..kinds, the one is from the feces of Aqua fortis, and the other from copperas. 1652French Yorksh. Spa vi. 62 The Colcothar..yields upon a refiners tast most pure Copper like to very gold. 1681tr. Willis' Rem. Med. Wks. Voc., Colcothar, dross of metals. |