Cooley's Cyclopædia of Practical Receipts and Collateral Information in the Arts, Manufactures, Professions, and Trades..., Sixth Edition, Volume II

by Arnold James Cooley; Richard Vine Tuson

With oxygen, ruthenium forms four compounds:—RuO; Ru₂O₃; RuO₂; and RuO₃.

Ruthenium Trichloride (RuCl₃), which is the most important of the chlorides, may be procured by dissolving the sesquioxide in hydrochloric acid. The solution being evaporated, the trichloride occurs as a greenish-blue deliquescent mass, which is soluble in alcohol.

Tests. In solutions of the trichloride, hydrogen sulphide gives a brown precipitate of ruthenic sesquisulphide, the supernatant liquid being of a bright blue colour. This reaction is a very delicate as well as a very characteristic one.

Metallic zinc reduces the yellow trichloride to the blue dichloride, the metal being afterwards precipitated as a black powder. Plumbic acetate gives a purplish-red precipitate, mercuric cyanide a blue one, the supernatant liquid being also blue. The caustic and carbonated alkalies throw down a black precipitate of sesquioxide of ruthenium, which is insoluble in excess of the precipitant. If the salts of ruthenium are boiled with sodic formiate or oxalate the solution becomes colourless, but no precipitate of reduced metal takes place.

Fig. 1.—Transverse section of testa, &c. × 108.

Fig. 2.—Coats in situ from without, × 170. a, External; b, Middle; c, Internal coat; d, Starch grains, × 108.

RYE. Syn. Secale, L. The seed of

Secale cereale, a gramineous plant, the native country of which is undetermined. It is a more certain crop and requires less culture and manure than wheat, and is hence largely cultivated in Germany, Russia, and in the northern parts of Europe, where it is extensively employed for bread. When roasted it is occasionally used as a substitute for coffee. It furnishes an excellent malt for the distillation of spirit, and is much used in the making of Hollands.

Rye bread is very likely to cause diarrhœa in those unaccustomed to partake of it. By continued use, however, this inconvenience disappears. Rye bread is acid and dark in colour. It is about equal in nutritive power to wheat. It is less abundant than wheat in fibrin, but richer in casein and albumen.