318 . Br. Walter Flight— History of Meteorites. 



The last paper written by the late Dr. Burkart gives the history 

 of the meteoric iron from Descubridora, Poblazon, near Catorze. State 

 San Louis Potosi, to which we have already alluded (see page 218). 

 It was found between 1780 and 1783; in 1856 it was conveyed to 

 the Amalgamation Works near Catorze to be used in the morteros or 

 stamping mills; and in 1871 was removed to Mexico, where it came 

 into the possession of the Geographical and Statistical Society. In 

 1872 this learned body came to a determination that the meteorite, 

 which weighs 575 kilog., should be broken up for examination, 

 which drew from the Mexican Natural History Society an indignant 

 protest. Those who take an interest in the correspondence which 

 passed between the two Societies will find below references to the 

 journals in which it appeared. 1 A portion of this iron is one of the 

 most recent additions to the University Collection at Gottingen. 



The iron, of which the author gives three drawings, is in the form 

 of a prism with rounded ends, and has a length of 90 cm. It has 

 a steel-grey colour, takes a high polish, and is remarkably malleable : 

 nails, knife-blades, wire, and a watch spring have been made of it. 

 When etehed it developes good figures, of which a sketch is given in 

 Burkart' s paper ; they resemble those of the iron of Xiquipilco ; the 

 angle 109° corresponding to an octahedron is frequently noticed. 

 Bounded masses of troilite occur here and there ; the hardness is 

 = 8 ; the specific gravity == 7*38. It has been analyzed by Patricio 

 Murphy with the following results : 



Iron = 89-51; Nickel = 8-05; Cobalt = 1-94; Sulphur = 0-45; Chromium 

 and Phosphorus — Traces. Total = 99-95. 



A very careful investigation has been made of the physical pro- 

 perties of the wire foi'ged from this iron ; it possesses an unusually 

 high elasticity, the modulus being = 7I36"17 kilog. ; the resistance of 

 the iron to rupture by compression = 38 kilog., to rupture by exten- 

 sion = 40 kilog. In each case the sectional area of the metal operated 

 on was 1 mm. square. The coefficient of the linear expansion of the 

 iron when heated between 0° and 100° C. = 0-00002336783. 



Meunier has investigated two of the Mexican irons, those from 

 Charcas and the Toluca Valley. A perfectly clear surface of the 

 Charcas iron appears to be naturally passive. A drop of copper sul- 

 phate, if allowed to evaporate at ordinary temperatures on its surface, 



Chihuahua. 2). Bonanza, State of Cohahuila. 3). Sierra Blanca, near Huaju- 

 quillo (or Jimenez), State of Chihuahua. 4). San Gregorio, State of Chihuahua. 

 5). Hacienda Concepcion, on the Bio Florido, State of Chihuahua. 6). Hacienda 

 Venagas, probably in the State of Chihuahua. 7). Plain near el Mercado mountain, 

 N. of Durango, State of Durango. 8). Durango (block used as an anvil; this mass 

 has recently been removed to Mexico). 9). San Francisco del Mezquital, State of 

 Durango. 10). Descubridora, at Poblazon, near Catorze, State of San Louis Potosi. 

 11). Charcas, State of San Louis Potosi. 12). Zacatecas. 13). A Hacienda south 

 (?) of Zacatecas. 14). Xiquipilco, Hocotitlan, Istlahuaca, etc., in the Toluca or 

 Lerma Valley, State of Mexico. 15). Chalco, Valley of Mexico. 16). Misteca Alta, 

 State of Oaxaca. 17). Tanhuitlan, State of Oaxaca. 18). (?) Bincon de Caparosa, 

 near Chilpancingo, on the road to Acapulco. 



1 Boletin de la Sociedad de Geografia y Estadistica, de la Republica mexicana. 

 Seg. Ep. Mexico, 1872. Tomo IV. Pages 5 and 317. — La Naturaleza Periodico 

 cientifico de la Sociedad mexicana de Historia natural. Mexico, 1873. Tome II. Pages 

 277 and 286. 



