On. the Affiiiilies of different Earths for Carlon. 231 



Exp. III. 400 grains of calcareous Ironstone, 



20 of carbon, or l-20th. 



The fusion of this mixture afforded a glass equally black, 

 but more shining than the last. A crystallized button of 

 steel was obtained which weighed 29 grains, and equal to 

 71 per cent. 



Exp. IV. 400 grains of ironstone, 



27 of carbon, of 1-] 5th nearly. 



The result as to glass was very similar to No. III. The 

 metallic button was coloured, and still more elegantly crys- 

 tallized. Its weight was found to be 3 7 grains, orl^:L per cent. 

 Exp. V. 400 grains of ironstone, 



40 ■ of charcoal, or 1-iOth. 



The result was a triangular-shaped button of crude iron, 

 which weighed 68 grains : equal to 17 per cent. 

 Exp. VI. 400 grains of ironstone, 



^^'^i; of carbon, or l-7th nearly. 



The chief part of this mixture was reduced to glass, and 

 detached globules of iron, which could not be collected with 

 any degree of accuracy. A portion of the mixture, very 

 magnetic, was found upon the surface of the glass. Th? 

 glass itself was of that pure flinty nature which always in- 

 dicates a saturation of coaly matter in the mixture. 

 Exp. VI {. 400 g-^-ains of ironstone, 



SO of carbon, or I-5th. 



The same circumstances were produced in this as in the 

 former experiment. A portion of very fine glass was formed, 

 more transpurcnt than in No. VI. The quantity of globules 

 appeared greater, though equally diffused. A much greater 

 portion oF the mixture remair.ed unfused, and which s^-emcd 

 to increase in proportion as the charcoal is auo;niented. 

 Recapitulation of experiments with first variety of calca- 

 reous ironstones : quantity of matter 400 grains. 

 Exp. I. Perse; no metal obtained. percent. 



II. I -30th of carbon yielded of metal 9 o-f-i. or 2-'- 



IH. l-20th ditto ' 29° or ^\ 



IV. 1-1 5th ditto 37 or 9]- 



V. l-ioth ditto 68 or 17* 



VI. I -7th ditto imperfect. 



VII. i-9th ditto ditto. 



Experiments made with the same calcareous ironstone in a 

 roasted state, after liaving ascertained that in torrefyino- 

 it lost of water and carbonic acid 42 per cent. 

 Exp. I. -100 grains of roasted ironstone, 



13} of carbon, or l-30th. 



1'4 This 



