METEORITES OF NORTH AMERICA. 501 



The hydrogen was tested for carburetted hydrogen but none was found. Neither arsenic, manganese, nor chro- 

 mium was found in this meteoric iron, and none of the minerals which are insoluble in acids and which are sometimes 

 met with in meteoric iron were detected in this specimen. 



The above examination shows that this specimen is different from that of the former meteorite from the same 

 locality. Even allowing for a discrepancy in the quantities of the constituents which might vary with the irregularity 

 in which the schreibersite, insoluble sulphides, and sulphate of iron are distributed in the nickeliferous iron, the entire 

 absence of carbon or graphite and chromic iron which, according to Bergmann, amount to 0.49 for carbon and 1.48 for 

 chromic iron, can not be considered accidental. 



Rose " described a specimen in the Berlin collection as follows : 



This is an iron of very characteristic structure which can only be seen in a large piece. Besides many small pieces 

 the Berlin Museum possesses an almost rectangular piece 1 inch thick, 3 inches broad and 3.5 inches long, cut from a 

 larger piece which was brought by Burkart from Mexico. Sides of the plate are in part formed by natural surfaces. 

 On an etched surface one sees that this iron consists of coarse granular pieces which are about 1 inch in diameter and 

 irregularly bounded, and that these consist of pieces lying parallel to the faces of the octahedron as in the iron meteorites 

 which give Widmannstatten figures. The component pieces are not very regularly bounded but their direction is 

 straight as one can see from the included schreibersite, which also shows, on cut surfaces, connected fine stria. Under 

 the microscope, however, one sees that these striae consist of single pieces which he beside one another in one or more 

 rows, or in single pieces in part regularly banded and lying in parallel position. They are thus incomplete crystals. 

 Included crystals of rhabdite do not occur, though the schreibersite in many pieces is so abundant and fine that one 

 could easily mistake the two. In certain lights one also sees a part of the component pieces shining, another part not, 

 though the latter shine if the lighting is different. Troilite is abundant in small irregular particles and is distinguished 

 by its dark color. It has a thin, coating of metallic luster which can not be distinguished from schreibersite; also small 

 particles of graphite within it. On the natural surface two round furrowed impressions occur which Reichenbach 

 considers to have been produced by the weathering out of troilite. 



Rose also gives a drawing of an etched section of Zacatecas and of schreibersite crystals 

 found in it. 



Cavaroz 12 gave the following note regarding the meteorite : 



In the same hacienda (Zacatecas) there is also a block of iron discovered a long time ago at Zacatecas. A small 

 portion of it was with great difficulty cut off to be carried to England for examination. The block which remains may 

 be 70 cm. in length, 30 in width, by 25 in thickness. It is irregularly rectangular in form. The upper surface is indented 

 with small rounded cups. The nature of the ground upon which this block was found and with which it had no relation, 

 and the peculiar quality of malleability belonging to this iron, create the presumption that the mass is of meteoric 

 origin. 



Reichenbach 13 makes frequent mention of Zacatecas, the most important of his observations 

 being as follows: 



It has a hard slag like crust which scratches glass easily and takes a fine polish. It is embedded in the angles of the 

 exterior surface and if present with the iron upon a polished section it is readily recognized by the fact that upon etching 

 the iron is more or less attacked all over, but the slag patches, somewhat reddish black in color, retain their glassy luster 

 unchanged. 



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It is grouped in class 9, group 1. This class includes all iron meteorites without Widmannstatten figures. * * * 

 The first group, in which Caryfort and Zacatecas are included, is not without certain marks which correspond in a 

 measure to Widmannstatten figures, but in a different and undeveloped way, and distorted on account of the inter- 

 mingling with much pyrites. 



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Others again (of the iron meteorites) show an entirely crystalline structure of a peculiar and distinct variety which 

 we never meet with upon nonmeteoric metal, such as * * * Zacatecas, * * * etc. 



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We consider next the fine Zacatecas meteorite which Burkart brought with him from Mexico. It consists of a 

 composition of many iron fragments the size of walnuts. But these fragments are seeded with numerous roundish, 

 elongated, and sometimes vermiform particles of pyrites from the size of hempseed to that of small peas. All are 

 rounded, nowhere jagged, and incompletely inclosed in the iron. * * * The magnetic pyrites is the older; the iron 

 is, moreover, the younger member of the compound. 



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Zacatecas shows the Widmannstatten figures upon the raw fracture without the labor of polishing or etching. 

 ********* 



If one would see a meteorite in which the swollen appearance as well as the grouping of the kamacite is especially 

 well developed he must turn to Zacatecas. There he will see the abundant inclusions of magnetic pyrites everywhere 

 enveloped in kamacite, arranged in every direction, and the outer surface of the kamacite diverted by pyrite, shaped 

 in all possible swellings and bendings. A large piece of Zacatecas weighing some 12 pounds, in my collection, which 



