METEORITES OF NORTH AMERICA. 91 



2. 1887: Whitfield. On the Johnson County, Arkansas, and Allen County, Kentucky, Meteorites. Idem, p. 500. 



(Analysis.) 



3. 1887: Kunz. The meteoric iron which fell in Johnson County, Arkansas, 3.17 p. m., March 27, 1886. Proc. U. S. 



Nat. Mus., vol. 10, pp. 598-655 (3 plates). 



4. 1895: Brezina. Wiener Sammlung, p. 283. 



CACARIA. 



Hacienda de Cacaria, State of Durango, Mexico. 



Latitude 24° 28' N., longitude 104° 5CK W. 



Iron. Octahedrite, Hammond Group (Oh) of Brezina. 



Found 1867; described 1889. 



Weight, 41.4 kgs. (91 lbs.). (Castillo.) 



The history and characters of this meteorite have been fully reported by Cohen " and a 

 translation of his description will suffice for purposes of this catalogue. His account is as 

 follows: 



BarceDa 2 first mentioned the Hacienda de Cacaria as a locality for meteoric iron and remarked that the Widmann- 

 statten figures consisted of four-sided fields. According to Castillo 6 the mass was rounded and weighed 41,422 grams. 

 It was found serving as an anvil in Durango, and according to the statement of the blacksmith, came from the Hacienda 

 de Cacaria lying 50 km. northward of Durango. Rath, who saw the meteorite in the National Museum in Mexico, 

 gave the distance from Durango as 42 km. To this mass belongs also the notice of Hapke 3 regarding the find of a new 

 iron meteorite weighing about 40 kg. near Durango. Further, according to the view of Fletcher, 6 the meteorite 

 noticed by Tarayre : in spite of the great difference in weight, 200 kg., belongs here. The mass mentioned by Tarayre 

 was also employed as an anvil by a blacksmith in Durango, and Fletcher thinks that two blocks could hardly be 

 employed in this manner in the neighborhood of Durango without this having been mentioned by one of the authors. 



According to Brezina 8 Cacaria shows unusual richness in nickel, but the kamacite is almost unaffected by acids. 

 He gives further characters, as follows: Kamacite and plessite equal; both coarse granular. As in Hammond, there 

 appear on etching in place of the tienite, black bands. At one point there is an appearance of tsenite 1 cm. long. 

 Regarding the similarity of the different iron meteorites obtained in the neighborhood of Durango, views differ. 

 Fletcher 6 thought that the iron masses known in literature by the names of Labor de Guadalupe, Rancho de la Pila, 

 and Hacienda de Cacaria, belonged to one meteorite fall. Meunier 7 seems to be of the same opinion, at least he unites 

 two of the pieces in the Paris collection having the labels Durango and Cacaria as Rancho de la Pila. He states that 

 they appear to be identical. 



He states the characters as: " Kamacite in somewhat bent lamellae ; very delicate tsenite threads, and plessite with 

 fully developed combs." From this description and the further facts noted below it is evident that the real Cacaria is 

 unrepresented in the Paris collection. 



Wiilfing 9 likewise, though only provisionally, urited the three above-named iron meteorites. Brezina, 8 on the 

 other hand, considers Cacaria a distinct iron and compares it with Hammond. According to him, the two form a group 

 of octahedrites in which the octahedral structure is produced by dustlike, carbonaceous particles in the place of the 

 tsenite, while Guadalupe and Rancho de la Pila are identical with the old Durango and belong to the normal octahe- 

 drites of medium width. Hapke, 3 who first had in hand the London Rancho de la Pila, described it as a normal octa- 

 hedrite, likewise later Fletcher. Regarding the two masses the following may be stated with certainty: 



First, the mass in the British Museum, weighing 46,512 grams, which was found in 1882 at Rancho de la Pila, was 

 placed by Fletcher by this name in the museum catalogue and, according to him, Brezina, and Hapke belongs to the 

 normal octahedrites. 



Second , the mass in the National Museum in Mexico which is of rounded shape and weighs 41 ,422 grams, and which 

 was found in 1804 at the Hacienda de Cacaria, is designated by Castillo, Fletcher, and Brezina as Cacaria and does 

 not belong to the normal octahedrites. 



Two pieces of •the latter mass which I have investigated agree in essential characters as regards their structure, 

 but are so different in chemical composition that a separate description of each seems necessary. 



First, Cacaria in the Vienna collection, obtained in Vienna from Castillo. On weak etching the mass of the nickel- 

 iron appears gray, weakly spotted, and slightly lustrous. This in general forms a subordinate groundmass of a homo- 

 geneous appearance composed of triangular, rhombic, and trapezoidal fields bounded by little black grains interrupted 

 by little tsenitelike particles with smooth, strongly shining faces, forming bands 0.05 to 0.2 mm. in breadth. These 

 bands to the naked eye appear sharply bounded. In reality they are not, since black points lie isolated in the nickel- 

 iron outside of the streaklike aggregations and at times are grouped in a dendritic manner, branching in the immediate 

 neighborhood of the more compact portions. The latter appearance is, however, visible on strong magnification only. 

 The generally rounded to oval, at times elongated, tsenitelike particles lie especially on the edges of the field, and are 

 bordered by rows of delicate black grains. On the edge of the piece, close to the natural surface, this tsenitelike 

 substance is developed to a length of a centimeter and branches thence into the neighboring nickel-iron. Owing to 

 the ductility of the mass it is not probable that schreibersite and cohenite are present. On strong etching the mass of 



