342 ACCOUNT AND DESCRIPTION 



nitrous gas. In the same masses are found malleable iron, 

 pyrites, and matter in an intermediate condition, intimately 

 blended, and adhering to each other. 



IV. The irregular black masses. 



Some of these appear somewhat regular, like crystals or 

 schorl, but, most of them are irregular. While examining 

 them, I found, in some, appearances of pyrites, in a state of 

 decomposition. This led to a suspicion, that these masses were 

 merely pyrites, which, by the force of the heat, had been de- 

 composed more or less completely. Accordingly, on separat- 

 ing a good many portions of these bodies, some were found 

 readily, others feebly, and others not at all attractable by the 

 magnet. But, the latter, by being heated, for a few minutes 

 with the blow pipe, became decidedly attractable. As a stand- 

 ard of comparison, some golden coloured pyrites from Peru, 

 were heated by the blow pipe, to expel the sulphur, and were 

 made to pass through all the shades of colour, and degrees of 

 magnetic attractability, corresponding with the various condi- 

 tions of the black irregular masses. No doubt could now re- 

 main that the conjecture concerning their nature was well 

 founded. The glossy interior coating, mentioned in the mi- 

 neralogical description, appeared to be of the same nature and 

 to approach nearly to the condition of malleable iron. 



V. The Crust. 



The black external crust adheres so closely to the earthy 

 matter within, that it is not easy to separate it. Indeed it ap- 

 peared scarcely worth while to subject it to a separate analysis, 

 since the blow pipe sufficiently indicates the difference between 

 it, and the rest of the stone. For, on heating any small portion 

 of the stone, with the most intense flame that a blow pipe can 

 give, it becomes covered with a black crust, similar to that of 

 the stone. The only point then in which the crust differs from 

 the rest of the stone is, that it has been changed by strong ignition, 

 having suffered a sort of vitrification, and its metallic parts a 

 partial oxidizement; I say partial, for when detached it is at- 

 tractable by the magnet, and the file discovers points of malle- 

 able iron. 



