552 Intelligence and Miscellaneous Articles. 



CHEMICAL AND MINERALOGICAL CHARACTERS OE THE 

 METEORITE OF ORGUEIL. 



Daubree, Cloez, Pisani, andDes Cloizeaux have communicated to 

 the French Academy papers on the physical and chemical charac- 

 ters of the Orgueil meteorite. In outward appearance it resembles 

 an earthy lignite. The dark mass contains minute grains of a bronze- 

 yellow substance having a metallic lustre and a high density, which 

 permits its easy separation from the main portion of the meteorite 

 by levigation : observed under the microscope, these particles are 

 seen to be distinct hexagonal tables ; they are strongly attracted by 

 the magnet, and have all the physical and chemical properties of 

 magnetic pyrites. A very marked characteristic of the meteorite is, 

 that when placed in water it falls to powder, and a portion of it is 

 in such an extreme state of mechanical division that it remains a 

 long time in suspension in the water, and passes through the closest 

 filter-paper. The density of the meteorite, taken in pure benzine, 

 gave Cloez 2'567. An analysis by this chemist shows it to contain 

 a considerable amount of magnetic oxide of iron, besides silicates, 

 protosulphide of iron, traces of nickel and chromium, 5*92 per cent, 

 of carbon (probably of the graphitic form), 9'06 per cent, of water, 

 and 5 '30 per cent of matter soluble in water, consisting of chlorides 

 of ammonium, sodium and potassium, and sulphates of magnesia, 

 soda, &c. It is decomposed by hydrochloric acid with evolution of 

 sulphuretted hydrogen, giving a greenish yellow solution and leaving 

 a black residue amounting to 7'6 per cent.; this residue when 

 heated with excess of air burns, and leaves a grey substance amount- 

 ing to 2*2 per cent. 



Pisani confirms the observations of Cloez as to the peculiar com- 

 portment of this stone when treated with water, and calls attention 

 to its porosity, and to the fact that this accounts for the facility with 

 which the sulphides have become oxidized to sulphates and hypo- 

 sulphites, and for the avidity which a dried specimen of it has for 

 water. An experiment showed that a specimen dried at 110° C. 

 absorbed 7 per cent, of water in a few hours when simply exposed 

 to the air. Pisani found 3*35 per cent, of matters soluble in water 

 in operating on about 18 grammes of the undried substance. This 

 contained hyposulphurous acid 0*48, sulphuric acid 1*40, chlorine 

 0*08, magnesia 0"30, lime 0'16, potash 0*60, soda, ammonia &c, 

 and loss 0*77. Alcohol took up 0*37 per cent, which proved to 

 consist chiefly of sulphur. Pisani's tabulated results give for the 

 composition of the whole meteorite : 



SiO 3 . MgO. FeO. MnO. CaO. NaO. KO. A1 2 3 . 



26-08 17*00 6'96 0-36 1'85 2*26 0-19 0-90, 

 together with chromic iron 0*49, magnetic iron 12*03, nickeliferous 

 sulphide of iron 16' 9 7, water and supposed organic substances 

 14-91 = 100. This gives for the oxygen ratio of the oxides and 

 silica 9-98: 13'90=3 : 4. 



Pisani proved the presence of magnetic iron by dissolving the 

 mineral in hot nitric acid, which decomposed the silicate and the sul- 

 phides, and left a black magnetic residue. The nickel was proved to 



