ferrous sulphide

Chem.: FeS. Sulphide of iron. Obtained by projecting into a red-hot crucible a mixture of five parts of sulphur with eight parts of iron filings, Also by rubbing a red-hot bar of iron with roll sulphur. Ferrous sulphide is a black, brittle substance, and is used in the laboratory as a source of sulphuretted hydrogen, H2S, that gas being liberated by the action of dilute sulphuric or hydrochloric acid on FeS. Hydrated ferrous sulphide is precipitated when ammonium sulphide is added to a soluoxygen rapidly from the air, and is converted into tion of a ferrous salt. This precipitate absorbs sulphur and hydrated ferric oxide. Ferrous salts are not precipitated by H2S from acid solutions. They give a white precipitate of ferrous hydrate with caustic alkalies and ammonia, which quickly oxidizes. Carbonates of pota ium, sodium, and ammonium precipitate white ferrous carbonate, which quickly becomes red-brown. Ammonium sulphide gives a black precipitate of ferrous sulphide. Pota ium ferrocyanide gives a pale bluish-white precipitate, which darkens in color on exposure to the air. Pota ium ferricyanide gives a deep-blue precipitate. fer-ru-gin-at-ed, a . [Lat. ferrugineus , ferru gin us , from ferrugo (gen it, fer rug in is ) = rust of iron; ferrum iron.] Having the properties or color of rusty iron. fěr-rû-gin-oŭs, fěr-rû-gin-ě-ous, a . [Lat. ferrugineus , ferruginus , from ferrugo ; Fr. ferru gineux; Ital.. ferruginoso .] 1. Containing particles of iron; partaking of the nature of iron. 2. Of the color of iron rust or oxide of iron. ferruginous-springs, s. pl. Geol.: Springs with much more than the normal amount of iron in their composition. They have a partly milky partly ocherous hue where the water stagnates, and cement the loose stones to which they have acce . For instance, a ferruginous spring which rises on the northern shore of the Firth of Forth, between Pitten weem and St. Monance, cements the pebbles of the beach into a conglomerate as hard as that of the Old Red Sand IMG:content-1564.png:[blocks in formation]