337 



It was afterwards presented by Lord Hawarden to the Geological Mu- 

 seum of Trinity College, where it is publicly exhibited. 



The stone weighed 4lbs. 14|- oz. It is rudely pyramidal in form ; 

 the triangular base being a freshly broken surface, and the faces of the 

 pyramid being covered by the usual black vitrified glaze. It is evi- 

 dently a portion of a much larger stone ; and as it appears from the 

 foregoing statement that its vertical velocity was not great, it is probable 

 that other pieces of the larger mass may yet be found in the neighbour- 

 hood of Dundrum. 



A singular feature is observable in this stone that I have never yet 

 seen in any other :— -the rounded edges of the pyramid are sharply 

 marked by lines on the black crust, as perfect as if made by a ruler. 

 This appearance is strictly confined to the surface, and seems to be a 

 result of some peculiar tension of the fused crust in cooling ; for no 

 trace of any continuation of the lines can be found in the interior of the 

 stone. 



On examination with the lens, specks of metallic iron and of magnetic 

 pyrites are visible, and also a few minute grains of chrysolith ; no other 

 minerals can be detected in the paste, which is of a dull grey, and of 

 loose texture, almost like a porous sandstone ; and the whole stone 

 would attract little notice, were it not for its specific gravity, and the 

 metallic particles visible in it. The specific gravity of this Meteoric 

 Stone, as is usually found to be the case, varied in specimens taken from 

 different parts of the mass. The portion analyzed was found to have 

 the following specific gravity : — 



Grs. 



Weight in air, . . . . 299*6 

 Weight in water, . . . 201 "9 



Difference, . . 97*7 grs. 



from which data the specific gravity is found to be, 



2996 



Specific gravity = -g— - = 3 *066. 



Other portions of the stone gave a specific gravity of 3*57. 



From 100 grs. acted on with iodine,* which dissolved out the alloy 

 of iron and nickel, there were obtained, of peroxide of iron, 27*95 grs., 

 and of protoxide of nickel, 1*20. 



* This method of investigation was suggested by Mr. William Early, Assistant in 

 the Laboratory of Trinity College ; the process consists in digesting the powdered mineral 

 in iodine with water for twelve hours, and proved to be completely successful, as was 

 shown by comparative trials on different portions of the powdered mineral. 



