Sir R. I. Murchison on a supposed Aerolite. 387 



well calculated, by his analytical researches, to settle the question on 

 a permanent basis. Should the metallurgical analyses now under the 

 conduct of Dr. Percy lead to the inevitable conclusion that the com- 

 position of this body is difFerent from that of well-authenticated 

 meteorites, and is similar to that of undoubted iron slags, we shall 

 then have obtained proofs of the great circumspection required be- 

 fore we assign a meteoric origin to some of these crystalline iron 

 masses, which though not seen to fall, have, from their containing 

 nickel, cobalt and other elements, been supposed to be formed by 

 causes extraneous to our planet. 



Postscript, 30th June 1855. — The following are the analyses above 

 referred to, which have been given to me by Dr. Percy since the 

 preceding notice was read : — 



"The slag-like /na«er ( 1 ) attached to the metal in the tree, as well 

 as the similar matter (2) with adherent metal which was found by 

 Mr. Reeks in the vicinity of the tree, has been analysed. The results 

 are as follow : — 



No.]. No. 2. 



Silica 58-70 63-52 



Protoxide of iron 35-46 32-30 



Lime 0-30 0-59 



Magnesia 0-74 0-21 



Protoxide of manganese . . trace trace 



Alumina 3-40 2-85 



Phosphoric acid 0-43 0-57 



Sulphur as sulphide trace trace 



9903 100-04 



" No. 1. was analysed by Mr. Spiller, and No. 2. by Mr. A. Dick, 

 chemists who have been incessantly engaged at the Museum during 

 the last two years and a half in the analyses of the iron ores of this 

 country, and whose great experience renders their results worthy of 

 entire confidence. Cobalt and nickel were not sought for in either 

 case, but the metallic iron enveloped in both specimens contained a 

 minute quantity of cobalt and nickel. Another piece of slaf-like 

 matter, which was found on the ground near the tree, and which 

 from its external characters I have no hesitation in ])ronouncing to 

 be a slag, was examined for cobalt and nickel, and gave unequivocal 

 evidence of the former in minute quantity, though not satisfactorily 

 of the latter. 



" The metal previously mentioned is malleable iron. That which 

 was detached from the slag-like matter, found outside the tree, was 

 filed and polished, and then treated with dilute sulphuric acid. 

 After this treatment, the surface ])resentcd small, confused, irregu- 

 larly-defined crystalline plates, and was identical in appearance with 

 the surface of a piece of malleable iron similarly treated after fusion 

 in a crucible." 



