readily soluble, yellow salts. The potassium salt, K,PW,028 + 20 (or 21) H2O, barium salt, barium ammonium salt, BaNH,PW,O Aq, ammonium salt, (NH,),PW,O28 + 20H2O, and silver salt, Ag3PW028+ 20H2O, are described. A. J. G. Physical Constants of Germanium and Titanium and their Compounds. By L. F. NILSON and O. PETTERSSON (Chem. Centr., 1887, 329-330).-Determinations are given of the specific and atomic heats of germanium and titanium and its oxide, and of the vapourdensities, critical temperatures, and vapour-tensions of some of the compounds of germanium. The atomic heats of germanium and titanium between the limits of temperature 100—0°, vary from 5:3—5·4, or about one unit less than the usual value; that of titanium increases with increase of temperature up to 777, at the temperature of sulphur vapour, whilst that of germanium remains constant. Vapour-density determinations of germanium tetrachloride, tetraiodide, and monosulphide are in accordance with the formula GeCl, GeL, and GeS. The critical temperature of germanium chloride is 276.9. V. H. V. Crystallised Compounds of Zirconium. By M. WEIBull (Ber., 20, 1394-1396).-Zirconyl chloride, ZrOCI, + 8H2O, is obtained crystallised in prismatic needles from a hydrochloric acid solution of the so-called zirconium oxychloride. The crystals belong to the tetragonal system, and give a:c1:031816. They are optically uniaxial, and show positive double refraction. Zirconyl bromide, ZrOBr2 + 8H2O, yields similar tetragonal needles. Zirconyl sulphate, Zr(SO4)2 + 4H2O, is obtained by the slow evaporation of a solution containing free acid. The hexagonal plates belong to the rhombic system, and show a : b: c = 0·6326 : 1 : 1·3350. L. T. T. Gold. By G. KRÜSS (Annalen, 238, 241-275; continued from this vol., p. 450).—The atomic weight of gold is found to be 196.669, as the mean of 30 analyses of potassium aurobromide and of a neutral solution of auric chloride. The results obtained from the analysis of sublimed auric chloride are somewhat lower, and are rejected by the author on the grounds that the sublimed auric chloride probably contains traces of free chlorine. The atomic weight of gold has recently been determined by Thorpe and Laurie (Trans., 1887, 565), who obtain the value 196.852. W. C. W. Alloys of Platinum, Iron, and Copper. By E. MAUMENÉ (Bull. Soc. Chim., 47, 39-41).-On heating 318 grams of platinum and 318 grams of iron with 666 grams of copper in a Perrot gas furnace, some of the iron remains unfused, but the fused portion of the metals forms a homogeneous alloy containing 7:43 per cent. of iron, 1965 per cent. of platinum, and 72.92 per cent. of copper. This alloy is very readily oxidisable, being quickly covered with a coating of iron oxide and copper carbonate when exposed to the air. A. P. Crystalline Alloys of Tin and the Platinum Metals. By H. DEBRAY (Compt. rend., 104, 1470-1472).-Platinum or an allied metal in the state of powder is fused in a porcelain crucible, with 20, 30, or even 50 times its weight of pure tin. Combination takes place with development of heat, and the alloy is allowed to cool slowly, and is then treated with dilute or concentrated hydrochloric acid, as the case may require. The crystalline alloy of platinum and tin is only obtained by the action of very dilute hydrochloric acid on an alloy containing not more than 2 per cent. of platinum. The regulus dissolves gradually, and leaves a residue of brilliant lamellæ of the composition PtSn. With a stronger acid, or with a smaller proportion of tin in the regulus, the residue is variable in composition. The alloy of tin and rhodium is obtained in small, brilliant crystals of the composition RhSn,, by the action of slightly diluted hydrochloric acid at 0°, on a regulus containing 3 per cent. of rhodium. The crystals are not affected by cold, concentrated hydrochloric acid. The iridium alloy is obtained in a similar manner from a regulus containing 6 per cent. of iridium. It forms small crystals of the composition IrSng, which are probably regular octahedra. When the regulus obtained by fusing ruthenium with 10 times its weight of tin is treated with hydrochloric acid diluted with an equal volume of water, the alloy RuSn, is left in small, hopper-shaped crystals. Osmium forms no similar alloy. The alloys were analysed by heating them to bright redness in a current of hydrogen chloride, when the tin volatilises, or by heating to redness the alloy mixed with twice its weight of sodium chloride in a current of dry chlorine. C. H. B. Action of Acids on Alloys. By H. DEBRAY (Compt. rend., 104, 1577-1582). The alloys of platinum and tin are somewhat readily attacked by hydrochloric acid even in the cold, whilst the alloys of tin with the other metals of the platinum group are not so readily affected (preceding Abstract). The residues thus obtained form black scales which resemble graphite, and contain in addition to the platinum metal a considerable proportion of tin, together with small quantities of oxygen and hydrogen. Their composition, however, is very variable. They behave like platinum-black, developing more or less heat when placed in an atmosphere of hydrogen, and causing the detonation of explosive gaseous mixtures. The development of heat is not merely a result of the condensation of the hydrogen in the pores of the substance, but is partly due to the partial reduction of the metallic substance and the consequent formation of water. Probably many substances which are called "platinum-black" are of a similar nature, and act in a similar manner. When the metallic residues are heated in a vacuum they lose water, and afterwards deflagrate without losing oxygen, and sometimes even become incandescent. They are more readily attacked by reagents than the metals which they contain. The residues from the rhodium, ruthenium, and iridium alloys are partly dissolved by aqua regia, but the action is never complete. The rhodium residue alters even when dried in the air. The residues still contain oxygen after having been heated in a vacuum, but they no longer have any catalytic properties. The alloys of zinc with the platinum metals yield similar residues, but that from the platinum alloy itself contains neither oxygen nor hydrogen, and does not deflagrate when heated. The rhodium residue deflagrates violently, and is almost completely soluble in aqua regia. The author has previously found that the alloys of the platinum metals and lead are attacked by dilute nitric acid, and yield black, explosive products (Abstr., 1880, 706). The alloy of rhodium with copper is completely soluble in nitric acid, and the alloys of copper with the other platinum metals dissolve in notable quantity, but leave black, explosive residues which contain the platinum metal, copper, nitrogen, and oxygen, but are very variable in composition. The iridium residue is mixed with metallic iridium in the form of a crystalline powder, which indicates that some of the iridium dissolves in the copper, and separates out on cooling. C. H. B. Mineralogical Chemistry. Native Gold from Thibet. By A. KALECSINSZKY (Zeit. Kryst. Min., 13, 73).-Native gold from East Thibet collected during Count Béla Széchenyi's expedition to Asia, gave on analysis the following results: Granular Limestones of Stainz in Styria. By E. HUSSAK (Zeit. Kryst. Min., 13, 52-54).-North-west of Stainz in Styria a bed of granular limestone containing felspar occurs in gueiss. The limestone contains microcline, albite, quartz, biotite, muscovite, tourmaline, hornblende, garnet, titanite, augite, and, occasionally, zoisite, zircon, chlorite, apatite, rutile, iron pyrites, magnetic pyrites, calcite, and, very rarely, orthoclase. With the exception of the microcline, all these minerals also occur in the gneiss enclosing the limestone. An analysis of the microcline gave the following results:— SiO2. Fe2O3. CaO. K2O. Na O. Ignition. Total. Al2O3. 19.75 trace trace 64.55 13.97 1.91 0.25 100.43 The sp. gr. is 2.561. From its analogy to Becke's microperthite, the author regards the name of microcline-perthite as the most suitable for the Stainz felspar. B. H. B. Manganese Apatite. Composition of Apatite. By M. WEIBULL (Ber., 20, 1525–1527).—Manganese apatite occurs in Westana, partly in reddish-brown masses, partly in crystals in pyrophyllite; the crystals are pale green, and more or less transparent; well-formed crystals are rare, sp. gr. 3.225 at 17°. In the following series of numbers, the column A contains those obtained by analysis; B the same number less the amount of lime corresponding to that of fluorine; in C the relation of the atoms are given : The numbers point to the formula Ca, (Mn) FO,(PO); _(comp. Völcker, Abstr., 1884, 162). N. H. M. Celestine in Nautilus Aratus. By W. STAHL (Chem. Zeit., 11, 508-509). The author has determined the composition of crystals found on the inner layer of a fossil Nautilus aratus from the Jura, near Rosswangen. The analysis gave corresponding to the formula BaCa,Sr2(SO4)23; the specific gravity of the crystals was 3.91. J. P. L. Artificial Formation of Alabandine. By H. BAUBIGNY (Compt. rend., 104, 1372—1373).—11 gram of manganese sulphate was dissolved in 150 c.c. of water, mixed with a slight excess of ammonium acetate and a few drops of acetic acid, saturated at 0° with hydrogen sulphide, and sealed up in glass tubes. After remaining at the ordinary temperature from four or five years, distinct, dark green, octahedral crystals were formed. These were not analysed, but there can be little doubt that they are alabandine or crystallised manganous sulphate. C. H. B. Artificial Production of Crocoisite. By L. BOURGEOIS (Compt. rend., 104, 1302-1303).-When lead chromate is heated with nitric acid diluted with 5-6 vols. of water, and the clear liquid decanted or filtered, it deposits crystals of lead chromate as it cools. The best results are obtained when the liquid is heated in sealed tubes, excess of lead chromate being avoided. The crystals are brilliant, deep orange-red, monoclinic prisms, which become crimson and then deep purple when heated, but regain their original colour on cooling. In crystalline form, optical properties, and other physical and chemical properties, the crystals are identical with crocoisite; sp. gr. = 6.29. C. H. B. Långbanite, a new Swedish Mineral. By G. FLINK (Zeit. Kryst. Min., 13, 1-8).-This mineral occurs at Långbanshyttan, in Wermland, in association with schefferite, and appears to be extremely rare. An analysis of 0-4117 gram gave the following results: SbOg. 0.0603 SiO2. 0.0448 Mn304. 0.2934 FeO3. 0.0472 The other substances were present in quantities too small to be estimated. The finely-powdered mineral was soluble in warm hydrochloric acid, no chlorine being given off. It may, therefore, be assumed that the iron and manganese are present as protoxides. The analysis would then be The formula suggested is 37Mn,SiO, +10Fe,Sb2O3. The mineral occurs only in the form of crystals. They belong to the hexagonal system; the axial ratio being a c 1: 16437. The following planes were determined with certainty :-Base, OP; prisms, coP, coP2; protopyramids, P, P, 2P; deuteropyramids, P2, P2, P2; dihexagonal pyramids, 3P, P. The colour of the mineral is an iron black with metallic lustre. It has a hardness of 6.5 and a sp. gr. of 4.918. B. H. B. Mineralogical Notes. By A. H. CHESTER (Amer. J. Sci., 33, 284-291).-1. Fuchsite.-This variety of mica occurs on Aird Island, in the district of Algoma, Canada, in a coarsely crystalline dolomite. An analysis of a pure sample, carefully separated from the accompanying mica, gave the following results: SiO2. AlOg. Cr,Og. CaO. MgO. KO. Na2O. H2O. Total. 45.49 31.08 3.09 0.51 3:36 9.76 0.90 5.85 100-04 The occurrence of chrome mica in Canada has been mentioned by Dawson; but no analysis has heretofore been published. The dolomite in which the fuchsite occurs is interesting on account of its peculiar appearance, which causes it to be readily mistaken for calcite. Analysis shows it to be a true dolomite in which part of the magnesium carbonate is replaced by iron carbonate. 2. Pink Celestine.-Celestine occurs at the stone quarries near Lairdsville in masses of prismatic crystals. It is interesting on account of its colour, which is usually pink, although sometimes the mineral has the ordinary blue tint. Analysis gave the following results : Sro. 46.71 BaO. CaO. SO3. SiO2. Total. 3. Zinkenite. This rare mineral has been discovered with antimony ores at the Stewart Mine, Sevier Co., Arkansas. * 100 38 in original. |
