440 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



No. 2 was dissolved in nitric acid. It gave: 



Iron 90.37 



Nickel 7. 79 



Insoluble residue. . . 1. 91 



100.07 

 Jordan 13 gave the following analysis: 



The piece of meteoric iron from Jiquipilco, Mexico, obtained from my friend, G. A. Stein, forms a complete indi- 

 vidual, whose form is somewhat comparable to that of a pear, if one views it lengthwise, compressed on three sides at 

 the thicker end and on two sides at the thinner end, somewhat bulged, the edges sometimes rounded and sometimes 

 sharp, and having finger prints, the deepest and longest of which are upon the under thicker end. If one proceeds 

 from the idea of an original easily altered general condition of the mass, he will be led to the type of the drop form, 

 while the irregularities of the surface may be referred to outside influences upon the still incompletely hardened 

 bodies. 



The weight was 5.5 pounds; the length, 17 cm.; the greatest width, 8 cm.; the greatest thickness, 7 cm. 

 The exterior portion of the mass consisted of an oxidized crust, like that of compact limonite, in part also like 

 that of limonite ocher, upon which golden drops of an iron sulphide solution appear here and there. A surface 4 

 by 2.5 cm. in size in the middle of the mass was covered with a thin film of fresh iron rust on portions of the crust, 

 amidst which file marks were to be seen. On these parts none of the before-mentioned drops were visible. 



For grinding the above-mentioned parts, which had already been attacked with the file, were utilized. There 

 the oxidized crust appeared to be of very uneven thickness, from that of a single card to several millimeters. The 

 Widmannstatten figures revealed themselves merely by polishing the surface and came out in all their beauty after 

 etching. They form, for the most part, larger and smaller parallelograms, sometimes rectangular, sometimes oblique, 

 and inclosed by small and not entirely straight threads of schreibersite, between which (parallelograms) trapeziums, 

 trapezoids, and triangles are interspersed. The form and grouping of the figures are exactly similar to those on a pol- 

 ished and partially etched, partially blued surface of the piece formerly belonging to Stein, the original 13-pound mass 

 which Doctor Uricoechea analyzed. In many threads of schreibersite on both pieces and especially upon the blued 

 surfaces, two plates closely twined together can be clearly distinguished. A look at these figures, here as in other 

 meteoric irons, led to the idea of the origination of this mass from an aggregate of individual, originally separated crys- 

 talline bodies, which in a still glowing condition were welded together by force of attraction. 



This iron is not passive, as proved by tests with copper sulphate. In the crust no other minerals were to be found, 

 no olivine and no schreibersite. 



For the analysis of this meteoric iron, which was made by Doctor Nason in Wohler's laboratory, filings from the thin 

 sections were contributed by Dr. Jordan. Five grams weight of this was dissolved in dilute muriatic acid. The 

 hydrogen gas evolved had only a very slight smell of hydrogen sulphide. The black, insoluble residue comprised 

 0.216 per cent. It was composed, as usually, of echreibersite. In general the following constituents were found: 



Fe 90.133 



NiCo 7. 241 



P 0. 376 



Insoluble residue 0. 216 



Iron sulphide Trace. 



Loss.. 2.034 



100.000 



The loss consisted at least for the most part of oxygen, and was due to the fact that the filings were somewhat 

 rusted. In the analysis this iron agreed very closely with that of the 220-pound mass from Jiquipilco, analyzed by 

 Doctor Pugh, and now in the possession of Stein. 



Burkart 14 gave the following account: 



This meteoric iron (Toluca) is not found in one large mass or in a few heavy pieces, but is distributed in many 

 small masses in the neighborhood of the Indian village of Xiquipilco. This town lies on the plateau of the Cordil- 

 leras of Mexico, scarcely two days' journey from the principal city of the land, in the valley of Toluca, on the upper 

 part of the Lerma River, or, as it is called farther down toward its mouth on the South Sea, the Santiago River, almost 

 3 miles from the river, between two of the higher mountains of Mexico, more than 12,000 to 14,000 feet above the sea, 

 namely, the extinct old volcano of Cerro de Hocotitlan and Nevada de Toluca, in the jurisdiction of Istlahuaca, 3 

 miles from the latter place and 6 miles north-northeast from the city of Toluca, upon the first elevation which bounds 

 the valley on the west. The locality as given by Boguslowski Toluca, near Xiquipilco is accordingly incorrect. 

 The Gazeta de Mexico, Del Rio, Chladni, Schreibers, Noggerath, and Partsch indicated the locality correctly and 

 have already made known the meteoric iron under the name of Xiquipilco throughout a wide circle. In recent 

 times numerous travelers have brought fragments of it to Europe. 



The earlier accounts state that the Xiquipilco iron was found in isolated masses of varying size and weight in the 

 neighborhood of the village above named, and was sought there by the Indians to be worked up into agricultural and 

 other implements. While I was living in the neighborhood of the valley of Toluca, I was informed that specimens 



