ˌprotoˈsulphide Chem.
[proto- 3.]
A compound of sulphur with another element or radical containing the minimum proportion of sulphur. Formerly also called protoˈsulphuret. (Now usually otherwise expressed: as protosulphide or proto-sulphuret of iron = ferrous sulphide, FeS.) So † protoˈsulphate, a salt formed by sulphuric acid with the protoxide of a metal, as protosulphate of iron, = ferrous sulphate, copperas, or green vitriol.
| 1856 Miller Elem. Chem. II. 726 Potassium..combines with this element [sulphur] in..five different proportions, KS, KS2, KS3, KS4, and KS6... The *protosulphide, KS [New Notation K2S], etc. c 1865 J. Wylde in Circ. Sc. I. 376/2 The proto-sulphide is..produced by passing sulphuretted hydrogen through a solution of a copper salt. |
| 1826 Henry Elem. Chem. II. 35 Two compounds of iron and sulphur have been proved to exist, the one with a smaller..proportion of sulphur..which is distinguished by the property of being magnetic, is the *proto-sulphuret. |
| 1819 J. G. Children Chem. Anal. 430 Sulphuretted hydrogen destroys the colour of the red compound of strychnine, as does..*protosulphate of iron. c 1865 J. Wylde in Circ. Sc. I. 146/1 Protosulphate of iron is well known under the name of green copperas. |