276 MEMOIR ON METEORITES. 



7.017. No regular crystalline form was detected ; its fracture 

 in one direction is conchoidal. It is attracted very readily by 

 the magnet, even more so than magnetic oxide of iron ; it ac- 

 quires polarity and retains it. I have a piece three tenths of an 

 inch long, two tenths of an inch broad, and one twentieth of an 

 inch thick, which has retained its polarity over six months ; 

 unfortunately the polarity was not tested immediately when 

 it was detached from the iron, and not until it had come in 

 contact with a magnet, so that it can not be pronounced as 

 originally polar. 



Before the blowpipe it melts readily, little blisters forming 

 on the surface from the escape of chlorine, and blackens. The 

 magnet is a most ready means of distinguishing the schrei- 

 bersite from the pyrites commonly found in meteoric irons; 

 for, although the pyrites is attracted by the magnet, it is neces- 

 sary that the latter should be brought quite near to it for the 

 effect to be produced; whereas if the particles exposed to the 

 magnet be schreibersite, they will be attracted with almost the 

 readiness of iron filings. 



Hydrochloric acid acts exceedingly slow on this mineral 

 when pulverized with the formation of phosphureted hydro- 

 gen. Nitric acid acts more vigorously, and readily dissolves 

 it when finely pulverized. The composition of this substance 

 has in all cases but one been made out from the residue of 

 meteoric iron, after having been acted on by hydrochloric acid, 

 which accounts for the great variation in the statements of the 

 proportion of its constituents. 



Mr. Fisher examined, pieces of schreibersite detached from 

 the Braunau iron with the following results: iron, 55.430; 

 nickel, 25.015; phosphorus, 11.722; chrome, 2.850; carbon, 

 1.156; silex, 0.985=98.158. 



The results of my analyses do not differ very materially 



from this. They are as follows : 



i 



Iron 57.22 



Nickel 25.82 



Cobalt 32 



Copper trace. 



Phosphorus 13.92 14.86 



Silica 1.62 



Alumina 1.63 



Zinc trace. not est. 



Chlorine .13 



•2 



3 



56.04 



56.53 



26.43 



28.02 



.41 



.28 



not est. 





100.66 



