304 0. C. Farrington — Analysis of "Iron Shale." 



same nature. Foo-te states that accompanying the pieces 

 found at the base of the crater were oxidized and sulphureted 

 fragments which were shown by a preliminary examination to 

 be undoubtedly of meteoric origin. Foote secured about 200 

 pounds of this material, varying from minute particles up to 

 pieces weighing 3 pounds 14 ounces. These fragments are 

 described as mostly quite angular in character, and a few as 

 showing ..a greenish constituent " resulting probably from oxida- 

 tion of the nickel." The oxidized material Foote states to be 

 identical in appearance to an incrustation which covers some of 

 the iron masses and partially tills some of the pits. In Koe- 

 nig's chemical examination published in the same paper he 

 states that " the iron is associated with a black hydroxide con- 

 taining Fe, Ni, Co and P in the ratio of the metallic part and 

 therefore presumably derived by a process of oxidation and 

 hydration of the latter." Foote evidently regarded the oxida- 

 tion of this material as having taken place during the fall of 

 the meteorite, as he states that " the remarkable quantity of 

 oxidized black fragmental material that was found at those 

 points where the greatest number of small fragments of mete- 

 oric iron were found, would seem to indicate that an extra- 

 ordinarily large mass of probably 500 or 600 pounds had 

 become oxidized while passing through the air- and so 

 weakened in its internal structure that it burst into pieces not 

 long before reaching the earth." Barringer's view of the 

 magnetic oxide seems to accord with this.* 



In Derby's account of the constituents of the Canyon Diablo 

 meteoritef reference is also made to what is undoubtedly this 

 same material. Derby's statement is as follows : 



" I was also shown in Washington schistose masses of iron 

 oxide found in the same region, whose connection with the 

 meteorite was considered doubtful. These closely resemble 

 the thicker masses of rust crust formed on the Bendego mete- 

 orite and like it, as is well seen in sections prepared by Mr. 

 Diller, show minute particles with a metallic luster which 

 were almost certainly grains of schreibersite, as that mineral 

 has been separated from the rust crust of both Bendego and 

 Sao Francisco do Sul. In view of its occurrence it can 

 hardly be doubted that these Canyon Diablo specimens are 

 due to secondary alteration of the meteorite. As the iron 

 masses in general have a thin rust crust, indicating consider- 

 able resistance to oxidation, it may be suggested that these 

 thicker masses of oxide may perhaps come from original 

 pyrite as in the case of Sao Francisco do Sul." 



It is thus seen that this material has been observed by pre- 

 vious investigators, but no detailed examination of it seems as 



*Or>. cit. p. 882. 



| This Journal (3), vol. xlix, pp. 102-110. 



