Dr. Walter Flight — History of Meteorites. 503 



felspar or an analogous mineral species. Though by their brilliancy 

 and transparency they resemble quartz, the feeble action which they 

 exert on polarized light suffices to distinguish them. In a microscopic 

 section the presence of a large amount of a black opaque ingredient 

 was recognized; grains of a sulphide with a sub-metallic lustre, 

 duller along the margin, are very abundant ; while others much smaller 

 and very blaok were identified with chromite. The stony matter 

 enclosing these substances is made up of two ingredients of different 

 aspect : the one, of a reddish-yellow colour and very transparent, 

 presents the flawed characters usually observed in the siliceous 

 portion of meteoric rocks; the other is of a darker hue and less 

 homogeneous. 



The material chosen for analysis, taken from the blackest, and 

 consequently less altered portion of the meteorite, had the following 

 composition : 



Nickel-iron 14-990 



Troilite 20-520 



Chromite 0-920 



Soluble silicate 38-688 



Insoluble silicate 24-640 



99-758 

 The nickel-iron consists of: 



Iron = 90-93 ; Nickel = 9-07 ; Total = 100-00 

 The troilite, constituting one-fifth of the stone, is present in larger 

 quantity than in any meteorite previously investigated. The siliceous 

 portions are composed as follow : 



SiOo A1 2 3 FeO MgO CaO Na a O K 2 Chromite 



A. Soluble 38-725 — 12-932 47-206 0-233 0-904 — — =100-000 



B. Insoluble 55-719 1-996 0-880 37-806 — — trace 3-599 =100-000 



The soluble portion consists chiefly of an olivine having the same 

 composition as that occurring in the meteorites of Tadjera and Pul- 

 tusk, while the insoluble part appears to be for the most part a pure 

 magnesian enstatite, with perhaps a small amount of the aluminous 

 mineral already alluded to. 



1858.— Trenton, Washington Co., Wisconsin. [Lat. 43° 22' N. ; 

 Long. 88° 8' W.] 1 



In the autumn of 1858 a farmer while working on his farm in Section 

 33, Washington Co., struck his plough against some hard object 

 about 10 inches below the surface ; it proved to be a mass of 

 meteoric iron weighing 62 lbs. It appears that four pieces, two of 

 which weighed 16 lbs. and 1\ lbs., were found, in the years im- 

 mediately following, within a circuit of two or three rods of the 

 spot where the largest was discovered. Dr. L. Smith gives the 

 weights of the masses: 62 lbs., 16 lbs., 10 lbs., and 8 lbs., and the 

 composition of the metal as written below (I.), side by side, with the 



1 J. L. Smith. Amer. Jour. Se., 1869, xlvii. 271. Mineralogy and Chemistry, 

 349.— F. Brenndecke. Annual Hep. Smithsonian Inst, for 1869, 1871, 417. — J. A. 

 Lapham. Amer. Jour. Sc, 1872, iii. 69. (See also Part I. Geol. Mag., page 30.) 



