on cerlc'm Utojly and Metalline Suhjlances. 51 



predion of hard bodies which were fituated there, and which, 

 when they came awav, left the furface of thefe cavities quite 

 fniooth, and having the laftre of poUfhed metal. Here and 

 there, in fome of thefe cavities, there remains a tranfparent 

 fubftance, of a yellowifh green colour, of which I fliall treat 

 more particularly when 1 come to the defcription of the fe^ 

 cond of the fpecimcns above mentioned. It is very clear that 

 the cavities here fpoken of owe their exiftence to this trans- 

 parent fubftance ; and that the polifh of the cavities arifes 

 merely from the compreffion of the faid fubftance, and is the 

 natural confequence of its furface having been in perfe6l con- 

 taft with that of the iron. 



This iron is very malleable : it may be eafily cut v/ilh a 

 knife ; and may be as eafily flattened or extended by means of a 

 hammer. Its fpecific gravity is 6487 ; which,'howcver, is very 

 much under that of iron which has been merely melted, and 

 has not been forcjed. The fpecific gravity of the native iron 

 of Bohemia, which is nearly as malleable and as eafy to be 

 cut, is ftill lefs: I found it not to exceed 6146. This low 

 degree of gravity appears to be owing partly to the oxidize- 

 mcnt of the furface of the iron, and partly to there being, 

 in the interior part of its fubftance, a number of fmall cavi- 

 ties, which are often rendered vifible by frafture, and which 

 have their furfaccs alfo oxidized. The frafture of this iron 

 prefents the fame (liining and filvery white colour as the com- 

 mon caft iron known by the name of white caft iron : but its 

 grain is much fmoother and finer ; it is alfo mucli more mal- 

 leable when cold. Bergman fays that this iron is brittle when 

 heated to a red heat. I have frequently tried it in that ftate, 

 and have conftantly 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 fpecimcns mentioned above, and 

 which weighs feveral pounds, prefents an afpe6l that differs, 

 in fome refpc6hs, from that of the preceding fpecimen. The 

 moft confidcrable part of it forms a foiid compact mafs, in 

 which there is not to be perceived the fmalieft appearance of 

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

 ramified or cellular part, fimilar, in every refiK'it, to llie fpe- 

 cimen already defcribcd, and every where completely con- 

 nerted with the fubftance of the mafs illelf. 



If the compaft part of this ))iece is examined with atten- 

 tion, it will be perceived that it is not entirely compoled of 

 iron in the metallic ftate, but that it is mixed with nearly 

 an eijual quantity of the tranfparent fubftance of a y<.llowifh 

 j;recu colcur, (lometimcs alfo of a greenifh yellow,) already 

 D a fpokcji 



