498 Dr. Walter Flight — History of Meteorites. 



small yellowish-green crystalline plate having the appearance of 

 mica was noticed. The specific gravity of the stone is 3-54:9, a 

 number intermediate between those yielded by the Pultusk and 

 Krahenberg meteorites. The Girgenti stone contains 8-3 per cent, 

 of nickel-iron having the composition : 



Iron = 87 3; Nickel = 12-7; Total = 100-0. 



Here again the proportion of this constituent is intermediate be- 

 tween that found in the meteorites just mentioned ; and in composition 

 nearly the same as the nickel-iron of Krahenberg. 



The non-magnetic portion, amounting to 91*7 per cent., which, 

 by reason of the small amount of material available for analysis, 

 was not subjected to the separating treatment of acid, was found to 

 consist of: 



Si0 2 A1 2 3 FeO MnO MgO CaO Na 2 ? Fe S Chromite 

 43-41 1-57 17-96 trace 26-84 1-85 1-50 3-43 2"24 1-20 = 10000 



If the chromite and the iron sulphide, which as it occurs in the 

 portion of the stone unacted upon by the magnet is probably troilite, 

 be deducted, the silicates have the following composition : 



Oxygen. 



Silicic acid , 46-61 -24-19 



Alumina 1-68 0-78 



Iron protoxide 19-22 4-33 



Magnesia 28'89 11-55 



Lime 1-99 057 



Soda (?) 1-61 0-66 



ioa-oo 

 The oxygen ratio of the total bases to that of the silicic acid is 

 1 : 1-352. As this is obviously a mixture of silicates, it seems not 

 improbable, both from the structure of the stone and the analytical 

 determinations, that it consists, as in the Krahenberg rock (see page 

 22), of an olivine of the form FeO, MgO, Si0 2 (like that also occur- 

 ring in the meteorites of Chateau-Renard and Kakova), and a nearly 

 pure magnesian enstatite, as the following scheme indicates : 



FeO, MgO, Si0 2 . MgO (CaO), Si0 2 . 

 Oxygen. Oxygen. 



Silicic acid 8-66 ... 15-53 



Iron oxide 4-33 ) „ „„ ... ■ 



Magnesia 433 °' DD ... 7 22 ) 7 . 7Q 



Lime ... 0-57 J ' ' 



For the reason already mentioned the presence of cobalt and of 

 the alkalies could not be directly determined. 



Found 1854.— Tucson, Pima Co., Arizona. 1 



This remarkable mass of iron, of which an account is given in 

 Bartlett's " Personal Narrative," 2 has been chosen by von Haidinger 



1 W. von Haidinger. Sitzier. Akad. Wiss. Wien, lxi. April heft. 



2 J. E. Bartlett. Personal Narrative of Explorations and Incidents in Texas, 

 New Mexico, California, Sonora, and Chihuahua. 1854. New York : Appleton & Co.' 

 Page 297. 



