Licence: Public Domain Mark
Credit: Qualitative chemical analysis / by C. Remigius Fresenius. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![frnm tlie ferrous state, as it existed in acid, the iron is converted fiom ^^^^ leiro , ^^^^ the solution of the sulphide to t^e feme s^^^^^^^^ the ix^on may be acid has been nearly neiitralized b^^ thrown down as basic salt eithex l^^^'^^^^^^^^^^^^ remain in by acetate of soda ^^^^^S- ,methods:- hn\r—^^^^^^^^ method *rpn into the warmed solution, all the zinc is Dnrowu uuw _ , nHde of zinc which is collected, and the manganese precipitated from the filSe by adding ammonik until alkaline, and then sulphide of ammonium^^^ ^^^^^^^ ^^^^^^ ^^^^^^^ ^ .^^fLtlfor may be present by sulphuric acid, concentrating, and adding potassa or 3s of cobalt and nickel, dissolved on the first t-atment of the precipitated sulphides with dilute hydrochloric acid, remain with h Sph^dfof zin'c in the separation of the latter by . or 6, or ^^th the protoxide of manganese if the separation is effected by c ihe sXS of zi^c may'be extracted from the blackish precipitate by dS hydrochloric acid, and the detection of the manganese in prefence of the cobalt and nickel may be readHy effected by means of carbonate of soda in the outer flame. ,^p+hnd In the presence of non-volatUe organic substances, the second method must be employed-namely, that depending on the prelmimary pre- cipitation of the whole of the metals as sulphides since such organic substances would check the precipitation of the ferric oxide by car- bonate of baryta. , . r i ^j-i^ov. Ferrous and ferric oxide may be detected m presence of each otJiei by testing for the former with ferricyanide of potassium, for the latter with ferrocyanide or sulphocyanate of potassium. Special Reactions of the rarer Oxides of the fourth group. § 113. a. Oxides of Uranium. This metal is found in a few minerals, as pitchblende, uranium-ochre &c The sesqnioxide of the metal is used to stain glass yell25^«V,fr«f n- V.^^^^^^^ forms two oxides, the protoxide named uranous oxide, UO UO.J, and the oxide or uranic oxide. UO3 [UO,]. The protoxide is brown or black ; it dis olves in nitric acid to nitrate of the oxide. The hydrate of the oxide is yellow; at about 300°, it loses its water and turns red; it is converted by ignition into * Equiv. 118*8, atomic weight, 2376.](https://iiif.wellcomecollection.org/image/b21966953_0157.jp2/full/800%2C/0/default.jpg)
