Another fpeci- 

 men ; more 

 Compact, 



155 ©N STOKY AND METALLINE SUBSTANCES 



and have conflantly found it to be malleable. The fame re- 

 mark may be applied to the native iron from South America; 

 and alfo to that from Senegal. 



The fecond of the two fpecimens mentioned above, and 

 which weighs feveral pounds, prefents an afpect that differs, 

 in fome refpects, from that of the preceding fpecimen. The 

 moit confiderable part of it forms a folid compact mafs, in 

 which there is not to be perceived the fmalleft appearance of 

 pores or cavities ; but there arifes upon its furface, a kind of 

 ramified or cellular part, fimilar, in every refpect, to the fpe- 

 cimen already clefcribed, and every where completely con- 

 nected with the fubftance of the raals itfelf. 

 confining of iron If the compact part of this piece is examined with attention, 

 tnwfparentmat- lt w '^ ^ e P erce * ve d> that it is not entirely compofed of iron 

 ter, which fills in the metallic ftate, but that it is mixed with nearly an equal 

 its cavities. quantity of the tranfparent fubftance of a yellowifh green co- 

 lour, (fometimes alfo of a greenifh yellow,) already fpoken of 

 in the defcription of the other fpecimen. This fubftance is 

 mixed with the iron, in fuch a manner, that if the -whole of 

 the former could be removed, the remaining part would con- 

 fift merely of iron in the metallic ftate, and would prefent the 

 fame cellular appearance as the preceding fpecimen, and the 

 ramified or cellular part of the fpecimen now defcribed. 

 The green /tony This ftony part, feparated from the iron, appears in the^ 

 Safe l°° kS Uke form of ,maI1 noduIes > generally of an irregular fbape, but 

 fometimes nearly globular : they have a perfectly fmooth and 

 mining furface, fb as very often to prefent the appearance of 

 fmall balls of glafs ; a circumftance that has led many perfons 

 to fuppofe them the refult of a real vitrification. Some of 

 thefe nodules have feveral irregular facets, produced by the 

 compreffion of the iron in which they were inclofed ; but I 

 have never obferved in them, any appearances that could lead 

 me to fufpect they had the flighteft tendency whatever to af- 

 fume a determined cryftalline form. 



This fubftance is always more or lefs tranfparent. It is 

 fufficiently hard to cut glafs ; but has no effect upon quartz. 

 It is very brittle : its fracture is ufually conchoid ; but I could 

 not perceive that it broke in any particular direction, in fuch 

 a way that I could confider the fracture as a natural one. It 

 becomes electric by friction. Its fpecific gravity is from 3263 

 to 3300. It is very refractory : I kept it, for fome time, ex- 



pofe4 



is always tranf- 

 parent} cuts 

 glafs, but not 

 quartz j frac- 

 ture conchoidal ; 

 electric by fric- 

 tion ; 





