evaporation of the brown solution shows that it has the composition 4(MnO2, H2O), Mn,O. The portion of the original precipitate which is insoluble in water has the composition Mn.Ŏ13,4H2O, or 3MnO2, Mn3O4, Mn2O3, 4H2O. The colloïdal manganese oxide is precipitated by salts more readily than colloïdal copper sulphide, and the valency of the metals in the salts has the same influence in both cases. The manganese solution can be kept for a long time in sealed tubes, but if filtered through paper the manganese is completely precipitated. C. H. B. Potassium Manganite. By A. JOLLES (Chem. Zeit., 11, 13941395). In a previous communication, it is stated that the following equation: KMnO1 + C2H2O = K2MnO3 + C2H2O + H2O, represents the oxidation which takes place in the author's test for certain impurities in chloroform (Abstr., 1887, 866). This statement has been contested. It is now shown that both aldehyde and the manganite K,MnO, are produced, but in excess of alcohol the latter soon decomposes; when, however, the substances are taken in equivalent. quantities, the manganite can be separated and dried over sulphuric acid. It is a yellowish-brown substance; is decomposed by dilute nitric and sulphuric acids, yielding manganese dioxide and hydrated dioxide and potassium nitrate or sulphate. It oxidises sulphurous acid to sulphuric acid, which in the nascent state forms manganese sulphate. Boiled with oxalic or tartaric acid, the manganite dissolves with evolution of carbonic anhydride. On exposure to a current of superheated steam and air, it is partially converted into manganate (compare Rousseau, Abstr., 1887, 552, 892). D. A. L. Manganese Compounds. By B. FRANKE (J. pr. Chem. [2], 36, 451-468; compare Abstr., 1887, 893, 1016).—By heating 8 grams of potassium permanganate with 100 c.c. of strong sulphuric acid at 100°, and allowing it to cool, a brown crystalline salt, Mn2O3,4SO,,5H2O, is formed. When this is treated with water, it is decomposed into equimolecular quantities of manganous sulphate and the hydrated oxide H,MnO,; the salt is probably Mn,(SO), H2SO. + 4H2O. Manganic sulphate, Mn(SO4)3, is obtained when the above salt is heated more strongly with sulphuric acid, in green crystals, decomposed by water in the same way as the acid salt, showing that the atoms of manganese are of different valency. The salt may therefore be regarded as the manganous salt of an acid, MnSO,(O-SO, OH)2, analogous to the manganous manganese chloride (Abstr., 1887, 893). Mn2(SO4)3,K2SO4, is obtained in red-brown crystals by carefully heating 8 grams of potassium permanganate with the mother-liquor from the above acid salt; water decomposes it in a manner similar to the other salts. Steel-grey, metallic-looking crystals of H,Mn2O, are obtained when either of the foregoing compounds is thrown into very weak aqueous soda; sulphuric acid decomposes it into manganous sulphate and manganous acid, MnO(OH)2, which is thus obtained pure as a brown powder; this points to the formula Mn<>Mn(OH)2. The brown colour of the solution of manganese dioxide in strong hydrochloric acid is caused by the presence of manganous acid. A. G. B. Permanganates. By T. KLOBB (Bull. Soc. Chim., 48, 240-244). -The author has previously prepared certain permanganates by adding potassium permanganate to ammoniacal solutions of certain metallic salts (Abstr., 1886, 983). He has now obtained similar derivatives from luteocobalt chloride in a similar way. Luteocobaltic permanganate, Co.(MnO,)6,12NH3, is obtained by mixing warm concentrated solutions of luteocobalt chloride (1 mol.) and potassium permanganate (12 mols.) It separates in the form of a precipitate mixed with a salt which crystallises in hexagonal plates, and is formed in greater proportion when the permanganate is not in excess. The latter can be removed by treatment with cold water, and the luteocobaltic permanganate is recrystallised from water at 60°. It then forms very brilliant, black tetahedra, only slightly soluble in cold water, but more soluble in hot water with partial decomposition. When heated, it detonates, and it also explodes when struck. With hydrochloric acid, it yields manganous chloride and luteocobaltic chloride. It is Luteocobaltic chloropermanganate, (Co2,12NH)C, 2MnO4, is prepared by mixing a solution of luteocobaltic chloride (8 mols.) with a solution of luteocobaltic permanganate (1 mol.), filtering rapidly, and allowing to cool. It separates in small, black lamella with the form of a regular hexagon, red or brown by transmitted light. very unstable, and is decomposed by water with removal of the chloride, but dissolves without decomposition in a solution of luteocobaltic chloride. When heated rapidly, it detonates, but it does not explode on percussion. Luteocobaltic bromopermanganate is analogous to the chloropermanganate, and is prepared in a similar way, or more simply, by mixing warm solutions of potassium permanganate (3 mols.) and luteocobaltic bromide (1 mol.), and allowing them to remain. It forms brilliant, hexagonal lamellæ, which are much more stable than the chlorine-derivative, and are not decomposed by boiling water. The salt which is obtained in the preparation of luteocobaltic permanganate, and which crystallises in hexagonal lamellæ, is also obtained by mixing cold concentrated solutions of luteocobaltic chloride (1 mol.) and potassium permanganate (3 mols.), when it separates slowly in violet hexagonal lamellæ of the composition (Co2,12NH3) Cl2,2KCl,4MnO,, very soluble in water with partial decomposition into its constituents. When heated, it behaves like the preceding salts. It may be regarded as a compound of luteocobaltic permanganate and luteocobaltic chloride with potassium chloride. It can also be formed by dissolving luteocobaltic chloropermanganate in potassium chloride solution, or by the action of luteocobaltic permanganate on a large excess of potassium chloride. C. H. B. Electrolytic Extraction of Antimony. By W. BORCHERS (Chem. Zeit., 11, 1021-1022).-The author has based a process for the extraction of antimony (from all its combinations soluble in sodium sulphide solution) on the electrolytic method of Classen and Ludwig (Abstr., 1885, 932) for the estimation of that metal. The ore is extracted with sodium sulphide solution, using 3 mols. NaS for every mol. SbS. The concentrated extract is mixed with 3 per cent. of sodium chloride to increase its conductivity, and electrolysed. According to the intensity of the current, the metal is deposited as a powder or in shining scales. To prevent deposition of sulphur, the relation of 1 atom of available Na for every atom of oxidisable sulphur must be maintained, but as the mixture Sb2S3 + Na2S + 2NaHO is too unstable, the above proportions are used; too much sodium sulphide is to be avoided as it increases the resistance of the liquid. The common salt is easily crystallised from the electrolysed solutions, and the sulphur recovered as sodium thiosulphate without much difficulty. D. A. L. Antimoniates. By G. v. KNORRE and P. OLSCHEWSKY (Ber., 20, 3043-3052).--Attempts were made to prepare Fremy's potassium antimoniate, K.Sb2O, (J. pr. Chem., 45, 209), but without success; it is concluded that that salt does not exist, and that Fremy's compound is a mixture of potassium antimoniate and potash. Potassium antimoniate, K2Sb2O, contains 5 mols. H2O when airdried, and is a white granular salt. 100 parts of water at 20° dissolve 2.81 parts of anhydrous salt. Sp. gr. of saturated solution at 18° = 1.0263. A table is given showing the loss of weight it undergoes at various temperatures; at 330° it contains rather more than 1 mol. H2O, and the author assumes that 1 mol. H2O is chemically combined, and that the formula of the air-dry salt is K2H2Sb2O; + 4H2O. When the hot aqueous solution is evaporated, a gummy salt remains; when this is dried at 100°, it has the composition expressed by the formula K,Sb2O, + 3H20. Potassium antimoniate was also prepared by the methods of Brunner (Dingl. polyt. J., 159, 356) and Reynoso (Annalen, 80, 272); details of preparation and results are given (compare Abstr., 1885, 1184). N. H. M. Mineralogical Chemistry. Arksutite from Ivigtut in Greenland. By A. E. NORDENSKIÖLD (Zeit. Kryst. Min., 13, 400-401, from Geol. Fören. Förhandl., 8, 172-175). A specimen of arksutite was separated according to Thoulet's method, and gave three different substances: an optically isotropic mineral having a sp. gr. of 3·12 (fluorspar); a mineral lighter than 2:99 (possibly thomsenolite); and a birefractive substance of sp. gr. 2.994, and giving on analysis the following results: = corresponding with the formula 5NaF + 3A1, F3. The composition of arksutite is thus perfectly in accord with that of the chiolite of Brandl. From the optical properties of the two minerals, there can be no doubt that they are identical. B. H. B. Mineralogical Notes. By G. FLINK (Zeit. Kryst. Min., 13, 401408, from Bihang till K. Sv. vet. akad. handl., 12, Afd. 2).-The author gives the results of a crystallographical and chemical investigation of the following minerals :-1. Cobalt-glance from Nordmarken; 2. Cosalite from Nordmarken; 3. Pyrochroite from Nordmarken; 4. Magnetite from Nordmarken; 5. Manganomagnetite from Lång6. Berzeliite from the same locality; 7. Monimolite from Pajsberg; 8. Xenotime from Hitterö, Norway; 9. Apatite from Nordmarken; 10. Liëvrite from Thyrill, Iceland; 11. Epidote from Nordmarken (28 new planes); 12. Epidote from Mörkhult; 13. Manganese-vesuvian from Pajsberg; 14. Orthoclase from the kraflite of Krafla, Iceland; 15. Titanite from the Fredriksberg Mine, Nordmarken. ban; The author also describes a new mineral, harstigite, from Pajsberg, named after the mine in which it was discovered. The mineral belongs to the rhombic system, and exhibits the forms coP, coPcs, P∞, ∞oP2, coP∞ɔ, P2. a:b: c = 0.7141 1: 1.01495. No cleavage was observed. The mineral is colourless, and has a vitreous lustre. Analysis gave the following results :— SiO2. Al2O3. CaO. MnO. MgO. KO. Na2O. H2O. Total. 38.94 10.61 29.23 12.81 3.27 0.35 0.71 3.97 99.89 B. H. B. Manganese and Uranium Oxides. By C. RAMMELSBERG (Zeit. Kryst. Min., 13, 418-419, from Ber. Akad. Ber., 1885, 97).-The author finds that both artificial Mn,O, and crystallised hausmannite, when boiled with concentrated nitric acid, or treated with dilute sulphuric acid, split up into 2MnO, which dissolves, and insoluble MnO2. Crystallised manganite is not decomposed by sulphuric acid in the same way. Powdered braunite undergoes decomposition, although not completely. Hausmannite should therefore be regarded as having the composition 2MnO,MnO2, whilst the formula of braunite is MnO, (Mn, Si) O2. The author gives the following new analysis of pitchblende from Joachimsthal : : The general formula of pitchblende is RO,RO2 = (UO2, Pb,Fe,Ca)O, (U,Si) O2 ; the formula of the varieties containing thorium is (UO2, Pb,Fe,Ca)O, (U,Th)02. The oxides, Y2O3, Eг2Oз, Cе2O3, which occur in several varieties of pitchblende, appear to be isomorphically mixed with the compound RO,RO2. The latter is thus analogous in constitution to braunite, which crystallises in a similar manner. B. H. B. Minerals from Carinthia. By A. BRUNLECHNER (Zeit. Kryst. Min., 13, 391-392, from Jahrb. nat. hist. Landesmuseums in Kärnthen, 17, 1—5).—Among the Carinthian minerals described by the author are the following:-Greenockite from Raibl, as a lemon-yellow coating on slate; garnet from Lamprechtsberg in the Lavanthal, as orange crystals enclosing copper pyrites; tourmaline from the same locality, in short, dark-brown crystals; zoisite from Stanziwurdikopf, green in columnar crystals in mica schist. Analyses are given of two specimens of siderite: I. Translucent crystals, with plane faces, from Wölch; II. Yellowish-white crystals, with curved faces, from Lölling : FeCO3. MnCO3. MgCO3. CaCO3. Impurities. Total. 0.25 99.99 100.22 In addition to other factors, the proportion of calcium, even in small quantities, appears to influence the crystal form of iron carbonB. H. B. ate. Martinite from the West Indies. By J. H. KLOOS (Jahrb. f. Min., 1888, i, Ref., 41, from Sammlg. geol. Reichsmuseums, Leiden).Martinite is a new calcium phosphate pseudomorphous after gypsum, from the phosphorite beds of the Island of Curaçao. The pseudomorphs occur in lenticular crystals, having the form of gypsum (-P, -Pco, coco). The crystals are colourless and transparent. Their sp. gr. is 2-892 to 2.896. Analysis gave the following results: P2O 47.87 CaO. 47.63 Loss on ignition. Total. 100.96 Fluorine is absent. The results of the analysis are in accord with the empirical formula 10CaO,4P205,3H2O. B. H. B. Diadochite from Visé. By G. CESARO (Zeit. Kryst. Min., 13, 421-422, from Ann. soc. géol. Belg., 12, 173).—The mineral from Visé, to which the name destinézite has been assigned, appears to be a variety of diadochite. An almost white and very pure specimen gave on analysis the following results : Fe2O3. PO5. SO3. HO. Hygroscopic H,O. C. Total. 0:30 1.40 100.26 The mineral on microscopic examination was found to belong to the monoclinic system. B. H. B. Mineral from Krems in Austria. By E. DRASCHE (Jahr. f. Min., 1888, i, Ref., 29-30, from Verh. geol. Reichsanst., 19, 81).-The |