253 Description and Analysis of a Meteoric Mass. 



parts. In some it is black, and has no metallic lustre ; in others, 

 it has a brilliant metallic lustre, and is then always much whiter 

 than steel or common iron. It is then but little susceptible of 

 being tarnished when exposed to the action of the air ; the black 

 part being merely tarnished, may be rendered white by a file j 

 in some places it is covered with a kind of black varnish. 



The substance which constitutes the greatest part of the re- 

 mainder of the mass, is graphite. This substance is not easily 

 distinguished from the common graphite or plumbago, except 

 that it is a little harder than the common granular and compact 

 varieties, and is also rather blacker, and makes a finer, blacker, 

 and more distinct line upon paper than common plumbago. 

 When rubbed with a hard body it assumes a bright metallic lus- 

 tre. It is not pure graphite, but rather a mixture of graphite and 

 metallic iron. The iron can be partly removed by a magnet 

 when the graphite is reduced to powder, but a considerable por- 

 tion remains mixed with the graphite, which, when acted upon 

 with hydrochloric acid, is dissolved with a brisk effervescence of 

 hydrogen gas. 



The sulphuret of iron, or pyrites, occupies the smallest portion 

 of the mass. This pyrites is not attracted by the magnet, nor 

 does it seem to act upon the magnetic needle. It can easily be 

 cut with a knife, and is consequently softer than common pyrites. 

 It does not give sparks when struck with steel, another property 

 which distinguishes it from common pyrites. It is easily soluble 

 in diluted hydrochloric acid, with a brisk evolution of sulphuret- 

 ted hydrogen gas, leaving a mixed powder of white and black in 

 the fluid. It has a more or less sub-lamellar structure, in which 

 no regularity can be perceived, and a color between bronze yel- 

 low and copper red, often tarnished. 



The hydroxide of iron, which forms part of this mass, is a 

 heterogeneous mixture of the varieties of the ore generally known 

 under the names of brown iron ore and yellow ochre, and resem- 

 bles this terrestrial mineral. Its color is generally brownish black, 

 passing into liver brown. The external surface of the mass is 

 covered here and there with the yellow earthy variety (yellow 

 ochre) ; how far this covering extended, I am not able to say, as 

 the mass was too roughly handled before any part of it came into 

 my possession. Its fracture resembles that of the common com- 

 pact brown iron ore. The blackish brown variety is so very 

 hard, that the best file is immediately dulled upon it, and leaves 



