Strontianite and Celestine from the Kaiserstuhl. By J. BECKENKAMP (Zeit. Kryst. Min., 14, 67—73).-Strontianite, a mineral hitherto unknown in Baden, has been found by the author at Oberschaffhausen. On analysis it gave the following results : : Total. 99.77 It occurs in prismatic crystals, and in crystals resembling tetrahedra, which are shown to be hemimorphic. At the same locality, the author found blue crystals of celestine. B. H. B. Chemical Structure of Natural Silicates. By F. W. CLARKE (Amer. Chem. J., 10, 120-128).-From the relatively small number of silicates and the repeated occurrence of the same silicates under the most varied circumstances, it follows that their constitution must be comparatively simple. They may generally be regarded as substitution derivatives of ortho- or of meta-silicic acid, or of polymerides of the same acids. To these views the author was led by noticing the change of topaz into muscovite (Al,SiO,F2 into Al,KH2(SiO4)3); these formulæ exhibit no distinct relationship until the former is trebled, and both are written as orthosilicates, Al(SiO1Al)1⁄2•SiO、(AlF2)з, and Al(SiO,Al), SiO,KH,. The following minerals are cited as being orthosilicates, and constitutional formulæ are assigned to them: Xenolite, fibrolite, paragonite, eucryptite, dumortierite, grossularite, prehnite, and natrolite; the formulæ exhibit relationships that are confirmed by the mode of occurrence of the several minerals. The same holds good with the alteration products westantite, montmorillonite, and kaolinite, and with the polymerides annite, sodulite, nosean, and ultramarine. The metasilicate of aluminium does not occur native; it might be written either SiO3(Al:SiO3)2, or Al(SiO3),Al, but as far as can be judged from the native metasilicates, the former formula is the only one admissible. Spodumene, jadeite, leucite, pyrophyllite, kyanite, are regarded as belonging to this class; the latter being represented as SiO, Al-O⚫AIO. There are also a couple of other silicic acids, H2Si2O,, from which petalite is derived, and H.Si,O,, from which only albite and orthoclase are derived. Other acids may exist, but it does not appear necessary to assume their existence. By these formulæ, relationships can be traced between minerals derived from the different acids as is shown in the case of muscovite, garnet, tourmaline, and orthoclase, and albite, the constituent of all granites. The silicates, other than those of aluminium, present few difficulties in the consideration of their structure. It is possible that silicates exist that are partly ortho- and partly meta-compounds. Similarly, all double salts may be considered, but with some, as the double haloïds, acetates, formates, &c., the case is not so clear H. B. Composition of Tourmaline. By R. B. RIGGS (Amer. J. Sci., 35, 35-51).—With the exception of the researches of Rammelsberg, very little has been done towards solving the question of the composi tion and constitution of the varieties of tourmaline. Rammelsberg's analyses were faulty in that the water and boric acid were not directly estimated. The direct estimation of water being possible, and a satisfactory method of determining boric acid having been devised by Gooch (Abstr, 1887, 299), new tourmaline analyses seemed desirable. The author has therefore analysed material from the following localities:-Auburn, Rumford, and Paris, in Maine; Calhao in Brazil; Dekalb, Gouverneur, and Pierrepoint in New York; Hamburg in New Jersey; Orford in New Hampshire; Monroe and Haddam in Connecticut; Stony Point in North Carolina; and Nantic Gulf in Baffin's Land. These represent well the variations in physical properties and chemical composition, which characterise the different varieties of tourmaline. From the analytical results, it is evident that there are three types, lithia, iron, and magnesia tourmaline respectively, with an indefinite number of intermediate products. These types graduate from one into the other, beginning with the lithia tourmaline, and passing through the iron varieties to those of the purer magnesian type. The following formulæ may be taken as representing typical compounds of the three varieties: I. Lithia tourmaline - 12SiO2,3B2O,,4H2O,8Al2O3,2 (NaLi),O. II. Iron tourmaline 12SiO2,3B203,4H,O,7A1,O,,4FeO, Na2O. 12SiO2,3B2O3,4H,O,5Al2O2,2MgO, Na2O. III. Magnesia tourmaline The calculated theoretical composition of these types is as follows: BO. SiO. Al2O3. FeO. MgO. Li2O. Na2O. H2O. Total. I. 11.00 37.70 42.75 1.57 3.21 3.77 100.00 2.90 3:49 100-00 2.18 3.74 100.00 II. 10-18 34.89 34-59 13.95 III. 10-90 37:38 26.49 19.31 On comparing these results with those of analysis, they will be found to agree closely. The boric acid found invariably falls short of the theory. This is not to be wondered at, as the analyses are made of material more or less impure, and the case would be exceptional where the impurity tended to raise the percentage of boric acid. The author intends to discuss more fully the composition of tourmaline in a paper which is to appear in a forthcoming bulletin of the United States Geological Survey. B. H. B. Genthite. By P. H. WALKER (Amer. Chem. J., 10, 44).—A fresh analysis of a sample from Webster, Jackson Co., N.C., U.S. (Compare Dunnington, this Journal, 1872, 680). Hardness 2·5; sp. gr. 2:53. SiO2. Nio. MgO. H2O at 100°. H2O above 100°. FeO3. 5.59 0.56 100-17 H. B. Nickeliferous Talc. By I. A. BACHMAN (Amer. Chem. J., 10, 45). The specimen was from Webster, Jackson Co., N.C., U.S. It is notable for the large amount of nickel contained in it:— SiO2. H2O at 100. H2O above 100°. 0.80 5:50 99.62 H. B. Tscheffkinite. By R. C. PRICE (Amer. Chem. J., 10, 38-39).The specimen, a large, single block, lying loose on the ground, is from Hat Creek, Massie's Mills, Nelson Co., Va., U.S. SiO2. TiO2. ZrO2. Ce2O3. DiО. LaО3. Fe2O3. FeO. BeO. Previous published analyses and also the present one approximate to the formula 2(Ca,Be, Fe, Mg)O, (Ce, Di, La, Fe)2O3,5(Si,Ti)O2. H. B. Zobtenite. By J. ROTH (Chem. Centr., 1887, 1235, from Preus. Akad. Wiss. Nat. M., 265-284).-Zobtenite is described as a petrographic rock belonging geologically to the crystalline schists, and corresponding to eruptive gabbro. The usual coarse-grained zobtenite is composed of saussuritic labradorite, grey or green diallage, some maguetic iron, and pyrites. The labradorite is mostly changed into an aggregate of zoisite and epidote with hornblende; the diallage into uralite. Serpentine and plagioclase-amphibolite occur in intimate association with the occasionally coarse-veined zobtenite. The same group of rocks is met with in the Baumgarten-Groschauer mountain, and the same interlacing of serpentine, hornblende schists, and zobtenite (veined gabbro) occurs also in Saxon granulite. This interlacing is seen very well at Rosswein, Böhrigen and Höllmuhle. Zobtenite here and there contains hypersthene and olivine. It is also found with chloritic schists and serpentine at Wagaleite in the Fichtelgebirge, and here is composed of saussuritic labradorite with coarse grossularite, diallage, and titanic iron. At Frankenstein, fine and coarse-grained zobtenite is found bearing hornblende, quartz, apatite, magnetite, iron pyrites, and more rarely rhombic pyroxene and secondary biotite. The widely distributed veined zobtenite found in the Jotunfjelds of Norway, is composed of plagioclase, sea-green diallage, hypersthene, green hornblende, apatite, magnetite, spinelle, and garnet, with transitions in the schists. The bright coloured labradorite rock of Närödal is composed of labradorite, diallage, and garnet.. The hyperytes of Vermland (plagioclase, augite, hypersthene, olivine, apatite, and titanic iron) change into dioritic rocks, and are intimately mixed with the surrounding magnetite gneiss. The modifications contain labradorite, green diallage with uralite, hypersthene, and garnet. In Roslagen, transitions of pure diorite through dioritic diallage to gabbro are found. The latter contains anorthite, diallage, hornblende, magnetite, olivine, augite, hypersthene, enstatite, apatite, mica, quartz, pyrites, graphite, epidote, saussurite, and small quantities of zircon and picotite. The gabbro of Radmansö is developed as gabbro, olivine-gabbro, and hornblende-gabbro, besides transitions occur as quartz, and biotite gabbro, and diallage gneiss. J. P. L. Meteoric Iron from Nejed, Central Arabia. By L. FLETCHER (Min. Mag., 7, 179–183).—A meteoric iron, weighing 594 kilograms, was seen to fall in the district of Nejed, Central Arabia, on June 18th, 1863. The mass is tetrahedral in shape, its length being 41 cm., and its breadth and thickness both 28 cm. The surface is covered with pittings, and there is no evidence of weathering. Analysis gave the following results: Fe. Insol. residue. Total. 99.79 Sp. gr. 7.863 Traces of copper and sulphur were observed. The black residue insoluble in aqua regia, consists chiefly of amorphous carbon containing a trace of chromite. In composition, the Nejed iron is very similar to the Trenton, Toluca, and the Verkhne Udinsk irons. B. H. B. Meteoric Iron from Greenbrier Co., West Virginia. By L. FLETCHER (Min. Mag., 7, 183-186).-A single fragment of iron, weighing 11 lbs., was found in 1880 on the Alleghany Mountain, Greenbrier Co., West Virginia. Two pieces, weighing 63 and 31 oz. respectively, were acquired for the British Museum. Analysis gave the following results: Fe. Ni. : Co. P. Residue. Total. Sp. gr. 91.59 7.11 0.60 0.08 0.12 99.50 7.869 The insoluble residue consisted of graphitic carbon, and a fine powder, small fragments, a thin elongated plate, and a single opaque black crystal with bright faces and a metallic lustre. These were found to be chromite. The existence of crystallised chromite in meteoric irons has hitherto not been completely established. The only instance appears to be recorded by Shepard in the iron of the Seneca River. The above percentage composition is approximately that of the Trenton, Rio Juncal, Seneca River, and Staunton irons. B. H. B. So-called Northport Meteorite. By F. C. ROBINSON (Amer. J. Sci., 35, 212-213).-A specimen of a black stone described as a meteorite which fell in Northport, Maine, gave on analysis the following results: Fe. Al. Cu. Mg. Co. SiO2. S. P. Total. Traces of manganese were observed. The magnesium, aluminium, and most of the iron were evidently combined as silicates. The rest of the iron was present as sulphide and oxide, and the copper as sulphide. Sections under the microscope closely resemble those made from furnace slag. It will be noticed, too, that the analysis corresponds very closely with published analyses of slag. In fact the socalled meteorite is identical in composition with copper-slag from the old Revere Copper Works in Massachusetts. Although there can be no doubt that this specimenn is an old copper-slag, still the fall of a meteorite at Northport cannot be questioned, and true meteoric fragments may possibly yet be found there. B. H. B. Organic Chemistry. Fire-damp. By C. WINKLER (J. pr. Chem. [2], 37, 254-258).— This is a controversial paper, in which the author states that many of the opinions advanced by Franke (this vol., p. 570) are not in accordance with those held by experts. G. T. M. Allylene. By A. BEHAL (Bull. Soc. Chim., 48, 788-799).—A number of experiments, made with a view to prepare symmetrical allylene, are described. The compounds employed were allyl iodide, trimethylene bromide, allyl alcohol, a- and B-epidichlorhydrin, &c. The experiments of Aarland (J. pr. Chem. [2], 6, 256) on the electrolysis of itaconic acid were repeated, but only negative results were obtained, from which the author concludes (1) that allylene, CH2:C:CH2, has not yet been isolated; (2) that it is possible that the compound is not capable of existing. Further, it is pointed out that the reactions hitherto employed for preparing allylene-(Hartenstein acted on B-epichlorhydrin with sodium (J. pr. Chem. [2], 7, 310)— ought to yield not this substance, but closed-chain compounds. N. H. M. Trichloralcohol: Action of Zinc Ethide on Aldehydes. By M. DELACRE (Bull. Soc. Chim., 48, 784-788).-40 grams of zinc ethide are dissolved in about 700 c.c. of absolute ether and gradually treated with an ethereal solution of 51 grains of chloral. After 24 hours, crystals of the compound ZnEtO-CH, CCl, separate. If 48 grams of chloral is now added to the mixture, a further reaction takes place, and zinc trichlorethoxide, Zn(O-CH2-CC13)2, separates as an abundant, white, pulverulent precipitate. Phosphorus trichloride acts on trichloralcohol with liberation of hydrogen chloride and formation of trichlorethyl phosphite. This is a clear liquid which fumes only slightly when freshly distilled. Phosphorus pentachloride reacts with trichloralcohol, yielding the compound CCl, CH,Cl; to complete the reaction, the mixture is afterwards heated at 140°. The new compound has an aromatic odour, melts at 73-74°, and sublimes; it is very soluble in ether, sparingly soluble in light petroleum. N. H. M. |
