436 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



TLACOTEPEC. 



District of Tecamachalco, State of Puebla, Mexico. 



Latitude 18° 45' N., longitude 97° 39' W. 



Iron. Octahedrite (O), of Brezina. 



Found 1903. 



Weight, 24 kga. (53 lbs.). 



The only mention of this meteorite seems to be by Ward, 1 who gives the above informa- 

 tion and states that the mass (weighing 24 kgs.) is in the Museum of the Instituto Geologico, 

 City of Mexico. 



BIBLIOGRAPHY. 



1. 1904: Ward. Catalogue of the Ward-Coonley Collection, pp. 25 and 98. 



TOLUCA. 

 Mexico. 



Here also Ixtlahuaca, Tejupilco, Xiquipilco. 

 Latitude 19° 24' N., longitude 99° 44' W. 



Iron. Medium octahedrite (Om), of Brezina; Caillite (type 18), of Meunier. 

 Known before 1776; mentioned 1784. 

 Weight: Several hundred masses, some weighing as much as 150 kgs. (300 lbs.) each. 



The first printed mention of this meteorite seems to have been in the Gazetas de Mexico, 1 

 in 1784, as follows: 



In the town of Xiquipilco, belonging to the district of Ixtlahuaca, native metallic iron is met with so pure that, 

 without any other preparation than heating, it may be worked into any shape; as I have verified in two journeys 

 undertaken with the object of discovering if there were any veins of this mineral which would be of infinite utility; 

 but my observations only verified the fact that masses of various shapes and sizes are found scattered through the 

 fields and that Indians keep a lookout for them, though the iron is at first covered with a crust of ocher. The Indians 

 of the town and the owners of the haciendas use no other for the fabrication of the necessary agricultural implements. 



Del Rio, 2 in 1804, gave as a Mexican locality for native iron: "Near Cuernavaca, in 

 Xiquipilco." 



Humboldt, 3 who had been in Mexico in 1803-4, says: 



It is to Sonneschmid that we are indebted for a knowledge of the meteoric iron which is found at several places 

 in Mexico, for example, at Zacatecas, Charcas, Durango, and, if I am not mistaken, in the vicinity of the small town 

 of Toluca. 



Chladni 4 repeated the account in the Gazetas do Mexico and mentioned a specimen of the 

 Toluca iron in the Vienna collection. 



Noggerath 6 gave the following data in a letter to Chladni, under date of June 25, 1826: 



I can now give you more exact indications concerning the place of discovery of the meteoric iron which I obtained 

 on the occasion of your recent visit to Bonn, and from which I permitted you to saw a specimen. It is from a letter 

 written by Mr. Wilhelm Stein, general agent for the German-American Mining Union, dated Mexico, April 23, 1825, 

 and sent to the address of the aforesaid Union at Elberfeld. Mr. Stein says, concerning the subject in this letter: 



"Among the minerals wliich I send you there is a piece of pure iron from Jiquipilco, 10 leagues northeast of 

 Toluca. The occurrence of this iron deserves to be more closely investigated. As yet there is little or nothing known 

 about it, and I was not permitted to clear up this uncertainty upon the occasion of my first trip to Jiquipilco, because 

 I was not so fortunate, despite my painstaking search, as to find a piece of the questionable iron in its place of discovery. 

 It is known, moreover, that a considerable quantity of this iron was found in plowing the ground in that vicinity, 

 and that it was used to make all sorts of tools. The accompanying specimen was given me as a present by John Gould, 

 a North American, who obtained it at the original locality." 



These data, therefore, largely confirm those which you have already given concerning this locality in your great 

 work on meteors (Wien, 1819), p. 338. 



I have etched a polished surface from the thick and compact piece of this iron which you saw in my possession, 

 and obtained quite distinct Widmannstatten figures. The bands intersect one another in two directions, and are 

 somewhat irregularly rectangular. The design is more distinct, but most resembles that shown by the polished sur- 

 face of the small specimen found in the Vienna natural history cabinet and figured by Schreiber in his Beitragen 

 (Wien, 1820), Plate VIII. Since the iron mass from Zacatecas does not entirely correspond to that of Jiquipilco, it 

 may be supposed that the aforesaid small Vienna specimen, which came from the larger one in the Klaproth collec- 

 tion, also originated from Jiquipilco. 



