MINERALOGICAL CHEMISTRY. lbl in er a1o g i c a 1 Ch emi s try. Syngenite. By V. v. ZEPHAROVICH (Jahrbuch. fur Mineralogie 1873 638-642). THISmineral from the salt-beds of Kalusz in Galicia having the com- position CaS04.K2S04 -+ H20,was originally supposed hy the author from its optical characters to belong to the rhombic syst.em although the external character is decidedly monoclinic. Further examination of the optical characters has shown however that the crystals are really monoclinic and this result is confirmed by exact measurement of the angles. The most frequently occurring forms are co em CORm OP COP4 OOPS COP.2 COP COP2-Pm7 .Pm 2Pm, 3R GO P 2P. The most exactly determinable angles are oc!42 co P m = 156"6' ; oP cog GO = 104'; P GO co P co = 100" 38' whence the ratios of the axes are- Clinodiagonal.Orthodiagonal. Principd axis. 1.3699 1 0.8738 lnclination of the clinodiagonal to the principal axis = 76". The crystals 'cleave perfectly parallel to co P 00 and co P. The plane of the optic axis is parallel to the orthodiagonal. The specific gravity of the mineral is 2.603 ; hardness = 2.5. In the flame of a Bunsen burner syngenite becomes turbid colours the flame violet and melts easily to a transparent bead which when cold is white and faintly lustrous and has a crystallogranular struc- ture. Heated in a tube the mineral decrepitates violently gives off water and melts after prolonged ignition to a milk-white mass. It is easily attacked by water 400 parts of cold water dissolving 1part of it.The clear solution becomes turbid when heated from deposition of gypsum. H. w. VOL. XXVII. L ABSTRACTS OF CHEMICAL PAPERS. Potassium Salt from India. By G. TSCHERMAK (Jahrbuch. fur Mineralogie 1873 642). THIS salt is a white or reddish hard granular mixture of sylvin (KJ3O.J rock-salt and kieserite (MgS04.H,0) occurring in the " Salt-range " in the northern Punjaub which belongs to the Silurian formation and is therefore perhaps the oldest of all known salt-deposits. The sylvin and rock-salt are easily recognised by their cleavage and flame-reactions. The kieserite which occurs in grains not exceeding 12 mm. in diameter is colourless and exhibits the hardness and density of that from Hallstadt ; here and there also it occurs massive ; when heated it gives off 12.99 p.c.water which agrees with the calculated quantity (13.04). As kieserite is converted by contact with moist air into bitter salt (MgS04.7H,0) the lumps of the mixture become pul- verulent on the surface and continually throw off crusts. Many of the lumps consist chiefly of sylvin. H. W. Schrockingerite a new Mineral from Joachimsthal. By A. SCHXAUF (Jahrbuch. fur Mineralogie 1873 646). THISis a calcio-manic carbonate crystallising in small soft thin six- sided plates implanted on pitch-blende in compact spherical or floccu-lent masses. It has a light greenish-yellow colour and nearly nacreous lustre. It contains scarcely perceptible traces of sulphuric acid. At a rcd heat it becomes orange-red like liebigite and gives off carbonic anhydride and water to the amount of 36.7 p.c. In forin it resembles the micas appearing yder t4he microscope as six-sided tables terminated by the faces 00 P 00 and 00 P. One of the principal planes of optical vibration is perpendicular to co I? 00 showing that crystals belong to the rhombic system. These characters show that schrockingerite as distinct from all the calcio-uranic carbonates pre-viously known. H. w. Jordanite from Imf'eld in the Binnenthal. By L. LIPOCZ (Jahrbuch. fur Mineralogie 1873 644). Two analyses of this mineral gave the following results- As. Pb. 5. I ...... 12.78 69-99 18.18 == 109.95 11... . . . 12.86 68.93 18.13 = 99.94 showing that its formula is As,Pb&. H. W. Titanic Iron Ore of Abnormal Composition.By HILGER (Jahrbuch. fur Mineralogie 1873 643). THEmaterial in question was taken from a splendid crystal of titanic iron in the mineralogical cabinet of the University of Wurzburg, supposed to come fi-om Norway. Analysis showed it to contain- MINEltXL00ICAL CHEXISTRY. 135 TiO? Fe203. FeO. 46.42 52.67 1-07 == 100.16 Reckoning the small quantity of iron nionoxide as sesquioxide the ratio of the latter to the titanic acid becomes Fe203 TiOz = 3 504 giving for the mineral the formula Fe20,.5Ti02. Rammelsberg distinguishes three principal classes of titanic iron ore viz. I. 11. 111. FeO.TiO,. iFe0 $MgO }TiO,. Different from these are- 1. A titanic iron from Harkau near Chemnitz analysed by Hesse having the formula 3Fe,0,.9Ti02.2. Iserin described by Rammelsberg having the composition Fe0.Ti02 + Fe20,.3TiOz. 3. From Uitkel on the Rhine described by Rammelsberg ; composi-tion 2(FeO.TiOZ) f 3(3Fe0.2FeZO3). H. W. Buchonite. By Ii’. SANDBERGER (Jahrbuch. fur Mineralogie 1873 647). A DESCRIPTION of this rock belonging to the nephelin group has already been given (p. 608 of last volume) together with an analysis by C. Gmelin of the variety occurring at Sinsheim. The medium- grained variety from the Calvarienberg at Poppenhausen on the Rhon has lately been analysed by E. v. Gerichten. Its specific gravity is 2-85. Its proximate constituents are nephelin partly in course of transformation into natrolite ; hornblende ; a micaceous minerd ; magnetic iron ore; triclinic and orthoclastic felspar ; apatite and augite.A large portion of it (40.73 P.c.) is decomposed by hydro- chloric acid with very distinct separation of gelatinous silica. This portion is therefore to the undecomposible portion in the ratio of 2 3 whereas in the Sinsheim rock this ratio is 3 4. The residue of the treatment with hydrochloric acid contains after the silver has been removed by sodium carbonate a very small qumtity of augite trans- parent colourless orthoclast ic felspar and a small quantity of triclinic felspar. Quantitative analysis gave a. Portion soluble in hydro-chloric acid (calculated to 100). b. Insoluble portion (calculated to 100). G. Total constituents- Si02. P205. Fe203.81203 FeO.CaO. MgO. K20. Na20. H20. a. 33.19 2.50 15.80 9.3’7 11.56 0.84 2.78 2.16 12.08 2-77 6 54-64 -14.46 10.68 2.34 7-15 0.44 5.25 5.04 -c. G.84 0.66 14.32 10.18 6-42 8.m 1.47 3.56 8.77 1*21-100*83 The small amount of magnesia and the large amount of iron in the insoluble residue show that the rock contains not basaltic hornblende but a hornblende rich in iron and poor in alkalis like arfvedsonite and L2 ABSTRACTS OF CHEMICAL PAPERS. the hornblende occurring in the ziivon-syenite of Brevig. Orthoclase occurs abundantly in the residue and is an essential constituent of the rock. Notwithstanding the difference of mineralogical character the total result of the analysis of buchonite is very much like that which Rosen- busch obtained for the porphyritic nephelinite of the Katzenbuckel (Jnhrbmh.1869 47). H. W. Analysis of two Minerals from Greenland. By 5.V. JANOVSKY (Deut. Chem. Ges. Ber. vi 1230-1232). THE first mineral (from the interior of Greenland) may from its mineralogical characteristics be regarded as one of the chlorite group. It has a dark green colour and gives a white streak. Before the blowpipe it mejts only at the edges. It is but imperfectly decomposed by hydrochloric acid even after long boiling. It contains-SiOP A120p FeO. CaO. MgO. H20. PZO,. F. S03. I.. 30.32 1'7.90 7.71 1.28 29.88 12.28 0.11 -= 99.48 11.. 29.82 17.96 '7.47 1.22 29-40 -tmce tmce leading to the formula- %&". + 4Aq or A12Si05+ R",Si20 + 4Aq. Err6Si3O16 The second specimen (from the island of Kikkertarsursurok) is a mineral similar to zircon-syenite.It contains quartz a hornblende-like mineral eudialite nephelin some magnetic iron and a triclinic felspar. The hornblende-like mineral is black transparent and green at the edges dark green when powdered. Before the blowpipe it easily melts into a black bead. It consists of Loss by SiOz. A1203. FeJ03.FeO. MnO. CaO. MgO. E20. N%O. P205ignition. I,. 4424 1.80 4-27 29.46 2.20 8.88 3.11 1.31 0.83 2.33 1*35=99.74 11.. a.06 --8.'78 --111.. 4427 -29.33 -8.82 3.03 --The formula which agrees most nearly with the above results is R~iR'&3,~0,~, or R'*Si207 + 15(RrrSi03). G. T. A. Examination of English Chalk. By A. VOGEL (N. Rep. Pharm. xxii 391). A SPECIMEN of English chalk used in the preparation of cement con- tained 98.5 per cent.of calcium carbonate 0.46 per cent. of calcium phosphate 0.786 per cent. of matter insoluble in hydrochloric acid. This insoluble residue contained 48 per cent. of organic matter and the organic matter contained 1.1per cent. of nitrogen answering to 7 per cent. of protein bodies. MINERALOGICAL CHEMISTRY. The incrustation produced in vessels supplied with water from the well at the University of Munich contains on the average 0.05 per cent. of phosphoric acid. G. T. A. Titanium and Vanadium in the Basalts of Clermont-Fer-rand (Auvergne). By V. ROUSSEL (Compt. rend. lxxvii 1102). THE percentage of titanium in the basalts of this locality is greater than that given in any published analysis of basalt.The lowest per- centage obtained in ten analyses was 0.707 and the highest 2.378 the mean being 1.501. The titanium is best determined as follows :-The basalt is fused with sodium carbonate the cooled mass dissolved in hydrochloric acid the solution evaporated to dryness and the silicic acid dehydrated as usual. The whole is then boiled with dilute acid and the silica filtered off both precipitate and fiItrate contain titanium. The silica is ignited and then treated with warm oil of vitriol for several hours. The pure silica is left insoluble after this operation and the titanium is precipitated froin the solution by ammonia. The original filtrate from the silica is boiled with sodium sulphate sul- phurous acid and sodium hyposulphite.The impure titanic oxide is gentlyignited and then mixed with that obtained from the silica and the whole digested in a sealed tube with warm concentrated hydrochloric acid. The residue is titanic oxide. The same basalts contain vanadic oxide the percentage of which varied in ten analyses from ,006 to *023,the mean being ,014. B. J. G. The Carbonic Acid of Vesuvius. B~DIEGO FRANCO (Ann. Chim. Phys. [4],xxx 87-114). THE author has made observat,ions of carbonic acid at the centre of Vesuvius under the lava of the great eruption of the 15th Kovember 1868 and in the stream of lava of the eruption of 1871. The details of his observations are too minute to be given but the results may be summarised as follows :-In every case the presence of carbonic acid has been demonstrated ; it is often but not invariably accompanied by sulphurous acid.Car-bonic acid is always to be found in the crater showing that it is not an " expiring effort " of the eruption but accompanies it constantly. None however was found in the extinct funlaroles at the foot of the mountain where the atmosphere was dry. It appears also that the evolution of aqueous vapour ceases after extinction. In the fumaroles resulting from the eruption of 1868 a large amount of carbonic acid is present which may be proved by passing the mixture of gases through lime water whereupon an abundant precipitate is thrown down. Carbonic acid was found ouly in small quantity in the lava from the eruption in 1871 and but a small amount of oxygen (from 6-12 per cent.).Nitrogen was the most abundant constituent of the gas evolved. The presence of CO may be explained by the amount of aqueous vapour present as it is always associated therewith. W. R. ABSTRACTS OF CHEMICAL PAPERS. Relation of Lime to Carbonic Acid in Well Water. By A. MATER (Landw. Versuchs-Stationen xvi 274-277). TESTborings into the gravel of the Rliine valley were made by the method employed for the Abyssinian wells with a view to the supply of Mannheim with water. Determinations of calcium existing as carbo- nate acd of total carbonic acid were niade in txenty-five samples of water thus obtained. The mean quantity of lime was 15.12 grams and of carbonic acid 31.09 grams per 100,000 parts. The mean proportion between them was 1 2.06 and the extreme proportions 1 1.57 and 1 2.45. The smallest proportion of carbonic acid to lime (1.57 1) is exactly that required to form calcium dicarbonate R. W.