104 IV.-On the Analysis of a Meteoric Stone and the Detection qf Va?mdium it. By RICHARD M.A. T.C.D. Proelector of Chemistry APJOIIN Caius College Cambridge. BEFORE the celebrated researches of Kirchof f and Angstrom which have proved the presence in the sun and fixed stars of many elements that occur on the earth our knowledge of the chemical composition of extra-terrestrial bodies was I may say entirely derived from the exami- nation of the meteoric stones or aaroliths which occasionally fall on the surface of our planet. The analysis therefore of these bodies has for a long time engaged the attention of many of the most eminent chemists. Howard Klaprot h and Vacq uelin and more recently Berzelius Ramm e Isberg and many others have investigated their composition and have clearly demonstrated the presence in them of 18 elementary bodies identical with those which occur in terrestrial minerals viz.oxygen sulphur silicium carbon phosphorus copper aluminium chromium iron mangmese nickel cobalt, calcium magnesium sodium potassium titanium and tin. Hydrogen clilorilie arsenic antimony and lead have also in some cases been detected in these bodies. The result of recent investigations in which I have been engaged relative to the presence of vanadium in traprocks (see Chem. News October 18 1873 page 183) led me to the conclusion that this metal is probably to be found in all rocks of this class; and as the proximate constituents of meteorites are in general the same as those of traprocks it seemed likely that vanadium would be found present in the former as well as the latter.I acco~dingly selected for examination 8 meteoric stone from the Mineralogical Museum of Trinit-y College Dublin which fell at Adare in the county Limerick in the year 1810. The surface of this stone is of a dark colour and exhibits a fused appearance doubtless the effect of the heating that it underwent during its rapid transit through the earth's atmosphere. On examining its recent fracture it appeared to consist of an earthy matrix in which were imbedded numerous small shining metallic particles. Its specific gravity was 3-94. In order to ascertain if vanadium was present the following course was adopted :-12 grams of the finely powdered mineral were digested with nitric acid and the whole evaporated to dryness the object of this first step being to oxidize the metallic particles.The residue was fluxed with four times its weight of sodium carbonate and the fused mass being permitted to cool a small quantity of nitre was added. The crucible was now cautiously heated care being taken that it did not APJOHN ON THE ANALYSIS OF A METEORIC STONE ETC. 105 attain more than a dull red heat. The mass was lixiviated with water and the aqueous solution was boiled with ammonium carbonate and filtered to remove silicic acid. Hydrochloric acid being added the filtrate was evaporated and hydrogen sulphide passed in to precipitate any metals of the lead group that might be present. The filtered solu- tion was then treated with an equal volume of a concentrated solution of ammonia and hydrogen sulphide was passed in till all the free ammonia was saturated.At this stage the solution assumed a beauti-ful intense cherry-red colour n sure indication of the presence of vanadium. This coloured liquid was filtered off and saturated with hydrochloric acid ;and the precipitate consisting of sulphur and vana- dium sulphide was dried ignited and the residue then melted with a pinch of nitre From the potassium vanadate thus formed the cha- racteristic blowpipe reactions of vanadium were obtained. The re- mainder of the potassium vanadate along with the microcosmic salt bead formed in the blowpipe experiment was dissolved in water acidulated with sulphuric acid and shaken in a test-tube with hydrogen peroxide and ether.The result was the formation of a dark red colour in the aqueous portion of the solution without the slightest trace of blue in the supernatant ether clearly demonstrating the presence of vanadium and at the same time showing that chromium was entirely absent. The discovery of vanadium iuduced me to make a quantitative analysis of this stone and as all the determinations were conducted with the greatest care a brief account of the methods I employed and of the results may not be destitute of interest. The separation of the metallic particles from the silicious portion of the stone was effected in the following manner:-10 grams of the finely pulverised mineral were digested for 24 hours with an excess of iodine and the insoluble portion was separated bp filtration.The excess of iodine having been removed from the filtrate by distillation with sulphuric acid the iron was precipitated with sodium acetate and the nickel and cobalt were separated in the filtrate by the potassium nitrite process. Two grams of the metallic particles which had been removed from the earthy matrix by means of amagnet were dissolved in nitric acid and on the addition of the molybdate solution gave it decided indication of the presence of phosphoric acid. It was present however as a mere trace. The portion deprived of metallic particles by iodine was now heated with dilute hydrochloric acid evaporated to dryness and exhausted with water and the several constituents of the aqueous solution deter- mined by known methods.The residue was boiled with a solution of pnre sodium carbonate in order to dissolve out the silicic acid which had been set free by the action of the hydrochloric acid. During the digestion with hydrochloric acid it was observed that 106 APJOBN ON THE ANALYSIS OF A BIETEORIC STONE ETC. hydrogen sulphide was copiously developed which indicated the pre- sence in the aikolith of iron sulphide. In order to determine its amount 2 grams of the original mineral were fluxed with sodium carbonate and potassium nitrate and the sulphur wits estimated as barium sulphate. From the sulphur thus found the quantity of magnetic pyrites was calculated and the amount of iron corresponding to it was deducted from that of the soluble silicate.The mineral portion therefore of this meteorite soluble in hydro- chloric acid consisted of a silicate and of magnetic pyrites. The residue insoluble in hydrochloi+c acid was fluxed with sodium carbonate and potassium nitrate and its various components were deter- mined in the ordinary manner. The chromic oxide obtained from this portion is in the discussion of the analysis assumed to be present as chrome iron. The alkalis of both the soluble and insoluble silicates were determined from large separate portions in order to insure greater accuracy in the results. A search for lithium by means of the spectroscope was insti- tuted but with an entirely negative result. The following is a statement of the proximate and ultimate composi- tion of the Adare meteorite as determined by my analysis :-I.Mi?teralogica,lcomposition. 11. Metullic portioiz. p.c. p.c. Metallic portion ..... 19.07 Iron .......... 85.120 Magnetic pyrites .... 6-54! Nickel ........ 14.2 75 Chrome iron ........ 1.75 Cobalt ........ ,602 Soluble silicate ...... 35.4 Phosphorus .... trace. Insoluble silicate .... 37.07 99.87 111. Silicate sohuble i?z hydrochlo-IT.8ilicute hsolubk $7~hydrochlo-ric acid. ric acid. p.c. p.c. SiO,. ..... 42.91 SiO,.. .... 5'3.48 A1203 .... 2.35 A1203 .... 3.24 FeO.. .... 16.93 FeO. .... 7.94 MnO .... 6.26 MnO .... 8-84 CaO.. .... 5.34 CaO.. .... 4.62 MgO .... 24.32 MgO ... 13.17 NhO .... -29 NazO .... 1.86 KZO ...... -02 KZO.. .... 0.30 Loss.. .... 1.58 PZO .... trace Loss.. .... 0.55