306 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



It seems correct therefore to separate Misteca and Yanhuitlan, the one as a medium and 

 the other as a fine octahedrite, but to learn the separate history of each seems impossible at 

 present. 



The first mention of Misteca as a meteorite locality seems to have been by Del Rio l in 

 1804. He gives "La Misteca " as a locality for metallic iron. A piece of meteoric iron acquired 

 by Partsch in 1834 for the Vienna Collection is described as "from an Indian town in the 

 Misteca, State of Oaxaca, Mexico." He states that it was brought from Mexico by Freiherr 

 von Karawinsky, of Munich. 



Bergemann 3 gave the following analysis (specific gravity, 7.58) : 



Fe Ni Co P S Insoluble 



86.875 9.917 0.745 0.070 0.553 0.975 =99.135 



Rammelsberg 8 obtained different values, as follows: 



Ni 4. 39 



Co 0. 18 



Insoluble residue 0. 20 



The discrepancy between these two analyses is marked and shows an error somewhere. 

 A new analysis of an undoubted Misteca specimen is desirable. 

 Buchner 5 described the structure of the iron as follows : 



Upon a freshly broken surface this specimen shows an almost silver-white color, a granular-flaky structure, and a 

 very distinct crystalline texture, while on other portions of the natural surface it is iron-black and covered with bubbly, 

 drusylike cavities from the size of hazelnuts to that of walnuts, which are covered over with a thin, firm material of the 

 color of brown iron ore. Inside, the mass is homogeneous, without clefts or cracks, and without visible admixture of 

 sulphide of iron or other foreign substances, the sulphide of iron first becoming noticeable after etching. By etching, 

 very beautiful Widmannstatten figures come out, whereby also the admixture of sulphide of iron and phosphide of 

 nickel-iron become visible, first in fine round portions, and, as it appears, less frequent than in the irons of Zacatecas 

 and Xiquipilco. The bands of the figures are 0.25 to 1 line wide, hatched with fine, diagonally intersecting lines, 

 and likewise dotted with fine white specks upon a gray background. The bands are divided from one another by 

 narrow, bright, brass-colored borders of a metallic luster, which also occur sometimes in the central areas, not, how- 

 ever, in continuous, but in broken and interrupted lines. They evidently consist of schreibersite. These border 

 lines appear most distinctly upon continuous surfaces against the bright brown or blue background, by reason of their 

 beautiful yellow color, where one also sees much more distinctly the middle areas circumscribed by such edges and 

 hatched with broken and often only dotted lines, which here and there approach so near again that the whole middle 

 portion appears yellow. 



Meunier 12 described the structure as follows : 



This is one of the irons which give the most perfectly characteristic figures of the caillite- type. The kamacite, 

 in medium bands, has a granular structure which takes on a sort of watered appearance upon etching. Tsenite is 

 present in extremely fine and continuous filaments. The plessite presents the same sort of combs and gratings. The 

 specimen in the Paris Museum does not contain an appreciable quantity of pyrrhotine. Schreibersite is found in the 

 residue after dissolving. 



The distribution of the meteorite is impossible to determine until it can be separated from 

 the Yanhuitlan specimens. 



BIBLIOGRAPHY. 



1. 1804: DEL RIO. Tablas Mineralogicas, p. 57. 



2. 1840: El Mosaico Mexicano, Bd. 3, p. 219. 



3. 1857: Bergemann. Untersuchungen von Meteoreisen. — Meteoreisen aus der Misteca im Staate von Oojaca. 



Ann. Bd. 100, pp. 246-249 (Analysis). 



4. 1858-1862: Von Reichenbach. No. 7, p. 551; No. 9, pp. 162, 174, 181; No. 10, p. 359; No. 15, pp. 114, 124; 



No. 16, pp. 261, 262; No. 17, pp. 266, 272; No. 18, pp. 484, 487; No. 19, pp. 150, 155, 156; No. 20, pp. 621, 622. 



5. 1863: Buchner. Meteoriten, pp. 148-149. 



6. 1869: Rammelsberg. Ueber zwei Meteoreisen aus Mexico. Zeitschr. deutsch. geol. Gesellsch., Bd. 21, p. 83 



(Analysis of Misteca alta and Yanhuitlan). 



7. 1885: Brezina. Wiener Sammlung, pp. 213 and 234. 



8. 1889: Castillo. Catalogue, pp. 2-3. 



9. 1890: Fletcher. Mexican meteorites. Mineral. Mag. vol. 9, pp. 96, 99, 102, 104, and 171-173. 



10. 1891: Cohkn and Weinschenk. Meteoreisen-Studien. Ann. K. K. Naturhist. Hofmus. Wien, Bd. 6, pp. 131, 

 165. 



