1856.] 129 



Xenntniss der Mineral Kiirper, B. 4, S. 101. Sonnenscbmit, Beschriebungder 

 vorzii/lichsten Bergsrerke. Reviere in Mexico 1804, S. 192 and 288. Cbaldni, 

 (U. F M. S. 336.) Partsch, (D. M. S. 99.) 



In the examiuation made by M. Berthein he failed to detect the presence of 

 cobalt, but it is mentioned by Prof. Clark that Manross had found it in a speci- 

 men from the cabinet of Prof. Wohler ; my examination confirms in this respect 

 that of M. Manross. 



To the kindness of W. S. Vaux, Esq., I am indebted for the material for this 

 investigation ; Mr. Vaux has in his magnificent cabinet the principal portion of 

 a mass which weighed over ten pounds. It was originally about six inches 

 long, with an average diameter of three inches ; the lump was oblong with 

 rounded ends, the whole beiug covered with a thin crust of limonite. 



A cross section cut from this lump has been carefully polished and etched 

 by strong nitric acid, which gives a most beautiful surface of about three and a 

 half inches in length by two and a half in breadth, covered with the greatest 

 complexity of widmannstellian figures which almost defy description. 



The surface is crossed by bands about one-tenth to one-sixteenth of an inch 

 In breadth ; these apparent bands are cross sections of different planes, as i8 

 readily perceived by their different refractive powers. 



On changing the position of the specimen those that are a bright silvery- 

 white in one direction, become a dull gray in another, and vice versa. 



There are several systems of bands, which preserve a parallelism among 

 themselves and cross other systems at various angles, forming trapezoids, rhombs 

 and triangles. These several fields and their characteristic etchings will be 

 described in detail at some future time. Along the bands or planes thin lami- 

 nae of schreibersite have been observed, as in other meteoric irons. 



Imbedded in one side of the large lump (just described) was a globule of 

 pyrrhi'tine, which looks as if it had been dropped into the iron when it was in a 

 semi-fluid state. This globule appears to have been about an inch in diameter; 

 it was in part decomposed, but a small portion of the mineral was separated 

 sufficiently pure for the determination of its specific gravity and analyses. On 

 dissolving it in hydrochloric acid, thin laminae of schreibersite separated with 

 minute portions of chromic iron. 



Through the kindness of Dr. F. A. Genth, I have been permitted to make the 

 following analyses in his laboratory : 



Pyrrhotine dissolved in nitric acid, gave 



Sulphur, - - _ - . 



Iron, ------ 



Nickel, 



Cobalt, - _ - - - 

 Silicon, --.--. 

 Phosphorus, - - - - 



99-27 " 

 No. 2. Dissolved in hydrochloric acid, gave 



Iron, ..._.- 58'25 per cent. 

 A residue remained, which was dissolved after being treated with hydrochloric 

 acid and chlorate of potash ; it consisted of 



Copper, .-.--- 012 per cent. 

 The remainder consisted principally of chromic iron, with a small portion of 

 schreibersite. 



The specific gravity was found to be 4-822. The ratio of sulphur to the metals 

 vas found to be 



Sulphur, 2-102 Iron, 2*066 "> , 



Nickel and Cobalt, 0-245 ) "''^"^ 

 It will be seen that the composition corresponds with that of pyrrhotine, con- 

 sidering its formula to be FeS, if we disregard the few impurities which were 

 found with it. 

 The meteoric iron was first treated in a flask with hydrochloric acid, and the 



