274 MEMOIR ON METEORITES. 



entirely free from it, while others again are covered with an 

 abundance of rust arising from its decomposition. 



Besides the above minerals two others were found — one a 

 siliceous mineral, the other in minute rounded black particles; 

 both, however, were in too small quantity for any thing like a 

 correct idea to be formed of their composition. 



The different minerals that admitted of it were examined 

 chemically, and the following are the results : 



1. Nickeliferous Iron.- — The specific gravity of this iron is, as 

 already stated, from 7.88 to 7.91. It is not readily acted on by 

 any of the acids in the cold; nitric acid, either concentrated 

 or dilute, has no action on it until heated to nearly 200° Fah., 

 when the action commences, and continues with great vigor 

 even after the withdrawal of heat. With reference to the 

 action of sulphate of copper, it is passive, although when im 

 mersed in a solution of sulphate of copper, and allowed to 

 remain for several hours, the latter metal deposits itself in 

 spots on the surface of the iron. 



Thorough digestion in hot nitric acid dissolves the iron 

 completely. When boiled with hydrochloric acid the iron dis- 

 solves with the liberation of hydrogen, leaving undissolved the 

 schreibersite ; but by long-continued action this latter is also 

 dissolved with the evolution of phosphureted hydrogen. 



The following ingredients were detected on analysis of two 

 specimens : i 2 



Iron 82.39 83.02 



Nickel 15.02 14.62 



Cobalt 43 .50 



Copper 09 .08 



Phosphorus .16 .19 



Chlorine .02 



. Sulphur ...... .08 



Silica 46 .84 



Magnesia ! .24 



98.55 99.57 



Tin and arsenic were looked for, but neither of those sub- 

 stances detected. The magnesia and silica are doubtless com- 

 bined, probably in the form of olivine, and disseminated in 

 minute particles through the iron. The phosphorus is in 

 combination with a given portion of iron and nickel, forming 

 schreibersite. The 0.16 per cent, of phosphorus corresponds to 

 1.15 of schreibersite; so the metal mass may be looked on as 

 composed of nickeliferous iron 98.97, screibersite 1.03=100.00 



