Experiments on various Earths, 161 



XV; — This- experiment was performed with 100 grains of 

 pure barytes, 200 grains of iron-stone, and 8 grains of 

 charcoal. 



The reasoning which suggested the use of iron-stone pro- 

 ceeded Upon the supposition that the surface incrustation 

 was an oxide of barytes (barytium), effected to a certain 

 stage of purity, in consequence of fusing pure barytes with 

 charcoal. It seemed probable that the addition of a second 

 affinity would, with the acid of the charcoal, tend to remove 

 the more fixed and ultimate portions of oxygen over which 

 the charcoal had no power. It was conceived that the iron- 

 stone, not being saturated with oxygen, might withdraw a 

 portion of that supposed to exist in the partially revived ba- 

 rytes, and tend to metallize the result. Malleable iron* as 

 in the other experiments, might have been used; but as this 

 would always have entailed the presence of a button of iron, 

 the result, it was supposed, would be attended with some 

 uncertainty. In the present experiment it was thought 

 proper to reduce the quantity of charcoal to eight grains, 

 lest any part of the iron contained in the oxide might thereby 

 be revived. 



This experiment being exposed to a similar heat as the 

 others, a flat blackish mass was obtained weighing 270 

 grains — loss of weight in the whole 38 grains. The iron- 

 stone alone ought to have lost 70 grains. It was therefore 

 inferred, that some new combination had taken place, and 

 what in other experiments would have been volatilized, in 

 this, became fixed. When the mass was divided, it exhi- 

 bited an uncommon appearance : the surface was covered 

 with a black de-vitrified glass ; the fracture showed a beau- 

 tiful metallic crystallization and brilliancy, with some large 

 metallic plates not unlike carburet of iron. Toward the 

 lower edges of the button the crystallization was very per- 

 fect. Although this mass had all the beauty and splendour 

 of a metallic regulus, yet there was a great deficiency of 

 metalline property : it was eagerly brittle, and easily reduced 

 to a powder ; exhibited little or no lustre in grain, or when 

 scratched with a knife point. This experiment was repeated 



Vol. 33. No. 130. Feb. 1809. I* under 



