16 Analysis of Iron Ores, &c. 



large quantity of lime, which the volatile alkali had precipi- 

 tated with the'help of" the oxide of iron. 



From these experiments, and the results they furnished, 

 it is evident, that the scoriae of the refining furnace, on 

 which .they were made, are formed of, 1st, a larce quantity 

 of iron oxided at a minimum ; 2d, oxide of manganese ; 

 3d, phosphate of iron ; 4th, chrome, probably in the state 

 of oxide) 5th, silex ; 6th, aluminc; 7th, lime, part of which 

 is perhaps combined with phosphoric acid. 



A doubt can hardly be entertained, that all these matters 

 were contained, at least in part, in the pig iron that fur- 

 nished Ihe scoria? : the charcoal might have imparted to them 

 at most some lime, silex, and manganese ; but the analysis 

 of the ores, and .of the pig iron itself, will soon teach us 

 what we ought to think on this point. 



III. Examination of the Bog Ores* 

 The ores subjected to analysis by M. Vauquelin were, 

 1st, those employed at the forge of Drambon. These are 

 in spherical nodules of different sizes. Some irregular frag- 

 ments of limestone are observed among them. 2d, those of 

 Chamfont and Grosbois. These much resemble the former. 

 Those of Grosbois contain a pretty large quantity of lime- 

 stone. 3d, that of Chatillon-sur-Scine. This is of an ochrey 

 yellow colour, in grains as small as millet-seed ; no lime- 

 stone is seen among it, but it contains a pretty large quan- 

 tity of clay, 



M. Vauquelin gives at large his analysis of the ore of 

 Drambon, observing, that the other ores include the same 

 principles, though in different proportions ; at the same time 

 the quantities he has assigned to its different component 

 parts he gives only as approximations. 



Ten grammes (154*5 grains) of the ore of Drambon, 

 treated with caustic potash, assumed a very intense green 

 colour, that communicated itself to the water in which it 

 was lixiviated. The ore, on being subjected to the same ope- 

 ration a second time, produced a similar effect, but less 

 striking. 



The 



