No. 2383. THE TROUP, TEXAS, METEORITE— UDDEN. 475 



adherent to the iron grains, from which some come out as extensions 

 or arms. The boundary between the two is in all such cases sharply 

 defined. 



The bulk of the siliceous material, which makes more than 90 per 

 cent of the mass of this meteor, is finely granular, the finest grains 

 measuring near one-sixth of a millimeter in diameter. This has a 

 gray color. The larger chondri are very light gray. The mineral 

 nature of this part of the meteorite has not yet been determined. 

 It can to some extent be inferred from the chemical analysis given 

 below. 



The specific gravity of this meteorite, roughly determined, aver- 

 ages 3.6. 



The chemical composition of the meteorite has been investigated 

 by Dr. E. P. Schoch, of the University of Texas, assisted by Mr. J. E. 

 Stullken. The following quantitative determinations were made: 



Per cent. Per cent. 



Na 2 3.86 



S0 3 8.23 



P 2 5 51 



C (graphite) 80 



Hg 2 (loss drying at 110° C.) 1. 10 



Ignition loss 90 



100. 03 



Si0 2 39. 68 



A1 2 3 3. 59 



Fe (metallic) 3. 10 



FeS 8.00 



FeO 22. 27 



CoO 42 



MnO 1.24 



CaO 2.03 



MgO 4. 30 



Doctor Schoch also makes the following observations : 



The total sulphur was found to be 6.20 per cent. Treating the sample with nitric 

 acid the free sulphur obtained was 2.91 per cent. This has been combined with iron 

 in the form of ferrous sulphide, which is found to be 8 per cent. The rest of the 

 sulphur (3.29 per cent) is in the form of sulphur trioxide, which amounts to 8.23 per cent. 



The total iron is 25.53 per cent. Metallic iron was found to be 3.12 per cent. The 

 iron in ferrous sulphide (8 per cent) equals 5.09 per cent. The remaining iron (17.32 

 per cent) is in the form of ferrous oxide, which amounts to 22.27 per cent. 



The other determinations were made by the usual method and did not give any 

 difficulty. 



This piece of meteorite had a black surface. It is easily broken. The fresh surface 

 thus exposed was brownish with many small black and gray specks. 



After crushing pieces of this meteorite in a mortar some hard black particles, vary- 

 ing in size up to a small pin head, were easily removed by a magnet and proved to 

 be metallic iron. 



The presence of sulphides was easily suggested when dilute hydrochloric acid pro 

 duced the odor of hydrogen disulphide. 



The residue unattacked by hydrochloric, nitric, sulphuric, and hydrofluoric acids 

 consisted of minute black particles, which proved to be carbon in the form of graphite. 



It was found that this meteorite was not strictly of uniform composition; the results 

 given represent somewhat of an average. 



