438 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



By saturating the hydrochloric acid solution with hydrogen sulphide, a small yellow precipitate was obtained 

 which appeared to be copper and tin. 



In 100 parts of the whole iron the following were found: 



Fe 90.40 



Ni 5.02 



Co 0.04 



X (equals schreibersite) 2. 99 



P 0.16 



Y (minerals) 1. 11 



Z (Cu, Sn, Mn, S) trace 



99.72 

 Pugh " reported an analysis as follows : 



Stein of Darmstadt obtained 4 masses of this iron, which weighed respectively 5.5 pounds, 13 pounds, 19.5 pounds, 

 and 220 pounds. The analysis of the 13-pound mass was made by Uricoechea (see above). Those of the 19.5 and 220 

 pound masses were made by me. 

 I. The 220-pound mass. 



It is covered with a tolerably thick coating of rust, in which are found many yellowish scales of schreibersite with 

 metallic luster. Many yellow drops of iron chloride are also found upon it, such as may be observed on many other 

 meteorites. These drops of iron chloride do not appear upon the polished section. 



This iron had a coarsely foliated, crystalline fracture and after etching it shows very beautiful Widmannstatten 

 figures very similar to those of the Elbogen iron. It is not passive. By dissolving in diluted muriatic acid hydrogen 

 sulphide is emitted, an evidence that it contains pure iron sulphide. Several tests left 0.9 and 1.24 per cent of a black 

 insoluble residue, consisting of schreibersite, graphite, and microscopical grains of a yellowish and a colorless mineral. 

 Two analyses of this iron gave: 



I II 



Fe 90.43 90.08 



Ni 7. 62 7. 10 



Co 0. 72 



X (equals schreibersite) 0.56 



P 0.15 



CuSn 0.03 



S 0.03 



Y (graphite and insoluble minerals) 0. 34 



Insoluble 1. 24 



99. 88 98. 42 

 II. The 19.5-pound mass. 



The exterior is much less oxidized than the larger mass, which may be due to the circumstance that the latter lay 

 in a dry river bed. Scales of schreibersite and an exudate of yellow drops of iron chloride were also noted. What 

 makes this meteoric iron especially noteworthy, however, is that it contains here and there, even in the middle of its 

 mass, small particles of greenish, granular olivine. It is unusually hard, much harder than the larger mass, so that it 

 is very hard to cut and quickly dulls the cutting tools. It has a coarsely foliated crystalline fracture. It yields very 

 complete figures upon etching. It is not passive. It develops no hydrogen sulphide gas in the process of dissolving 

 in muriatic acid. Tests from different parts left 0.568 per cent and 1.58 per cent of insoluble black residue, which 

 consisted of schreibersite, graphite, and transparent grains of a colorless, a ruby red, and a greenish mineral. 

 Three analyses of this iron gave the following results: 



I 



Fe 87.894 



Ni 9.056 



Co 1. 070 



P 0.620 



X (equals schreibersite) 0. 341 



Mn 0.201 



CuSn traces 



Y (graphite and minerals) 0. 224 



99. 406 99. 000 99. 726 



It is evident that this iron is distinguished by an unusually high percentage of phosphorus and cobalt, which may 

 account for its extreme hardness. 



Taylor u made an examination and analysis of the iron with the following results : 



The meteoric iron from Xiquipilco, Mexico, appears to have been first mentioned in the Gazeta de Mexico in 1784. 

 It is stated there that small pieces of native iron, from a few ounces to 50 pounds in weight were very numerous, which 

 were sought for by the Indians after heavy rains, who used them for manufacturing agricultural implements. 



