298 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



The samples submitted were cut from the outer portion of the meteorite, including the oxidized crust; this was 

 carefully removed by scraping and filing. There was a small quantity of rust in the cracks on the cut surface, but its 

 amount was trivial. 



During the solution in aqua regia scales of schreibersite were observed. A few email black grains were left which 

 showed crystal faces under the mitroscope, and which were identified as chromite by the usual reaction. A minute 

 amount of colorless granular matter was also noted, the nature of which could not be determined. 



All determinations were made in a solution of the same portion of 3.8536 grams, the residue having been brought 

 into solution and added. 



The analysis gave: 



0.9659 gram. 1.9318 grams. 



Fe 89.68 



Ni 9.20 



Cu 0.037 



Co 0.33 



P 0.158 



S 0.017 



Cr. . . trace 



99. 422 

 From the above data the composition of the iron may be expressed as follows: 



Nickel-iron (Fe, Ni, Cu, Co) 98.31 



Schreibersite 1. 06 



Troilite 0. 05 



Chromite trace 



Fe s Oj trace 



99.42 

 The mass is chiefly preserved in Baylor University, Waco, Texas. 



BIBLIOGRAPHY. 



1. 1900: MERRILL. Proc. Washington Acad. Sci., vol. 2, pp. 51-53. (With a plate showing the shape of the mass and 



etching figures.) 



2. 1901: CHARLTON. Trans. Texas Acad. Sci., vol. 4, pp. 83-84. 



Maverick County. See Fort Duncan. 



MAZAPIL. 



Zacatecas, Mexico. 



Latitude 24 31' N., longitude 101 59' W. 

 Iron. Medium octahedrite (Om) of Brezina. 

 Fell 9 p. m. November 27, 1885; described 1887. 

 Weight, 3,950 grams (9 Ibs.). 



The first description of this meteorite seems to have been by Hidden ', as follows: 



Among the large number of meteoric irons which have been described only eight are recorded as having been seen 

 to fall. It is my privilege to be able to add a ninth fall to this short list and one which may prove to be of exceptional 

 scientific importance. This mass of meteoric iron I received in August last as a gift from my friend, Prof. Jose A. y 

 Bonilla, director of the Astronomical Observatory at Zacatecas, Mexico. He stated that it was seen to fall at about 9 

 p. m. on November 27, 1885, during the periodical star shower of the "Bielids." Such is the great interest of this 

 meteorite as shown by its history that I have delayed announcing it until the evidence of its fall had been substantiated 

 as thoroughly as possible. 



The general freshness of surface, which shows very perfectly the flow of the melted crust; the presence of unusually 

 large nodules of a very compact graphite; the very slight superficial oxidation, and its dissimilarity to other meteorites 

 of the region, are all interesting features of this iron, and serve to confirm the statement of its recent fall. When received 

 it weighed about 3,950 grams. Its present weight is 3,864 grams. Its greatest length, diagonally across the mass, is 

 175 mm. In its thickest part it measures about 60 mm. It could be described as a flat irregular mass covered with 

 deep depressions and having a smooth surface. 



The evidence of the fall is set forth in the following communication (translated) from Professor Bonilla: 



"It is with great pleasure that I send to you the uranolite which fell near Mazapil during the night of November 

 27, 1885. That you may the better appreciate the great scientific interest which this uranolite possesses I will state 

 that everything points to the belief that it belongs to a fragment of the comet of Biela-Gambert, lost since 1852. I 



