86 On the AfflnUles of different Earths for Carlon^ 



The result of this was a well shaped button of iron which 

 weighed 58 grains; equal to 29 per cent. 



Exp. II. The same oxide - - 200 grains. 



Charcoal 1-lOth, or - 20 



Chalk one-half ^ - 100 



■ This mixture was carefully and completely fused. A po- 

 lished looking button of metal was found weighing 35 

 grains; equal to ly^r per cent: being 23 grains, or 11^ 

 per cent, less than Exp. I, and inexplicable upon any other 

 grounds than in consequence of the introduction of calca- 

 reous earth. 



jE.rp. III. Oxide same as formerly - 200 grains. 



Charcoal 1- 10th - - 20 " 



Chalk l-4th, or - - 50 



The result bv fusion yielded a perfect button of metal 

 weighing 43 grains : equal to 2H per cent. In this expe- 

 rimeut the chalk being less than in former by one-half, the 

 metallic product increased S grains, or 4 per cent. 



£a;/j. IV. Oxide as foVmerly - - 200 grains. 



Charcoal 1-1 0th - - 20 



Chalk l-8th - - - 25 



A metallic button was obtained from the fusion of this 

 mixture, and found to weigh 49 grains : equal to 24-i- per 

 cent. In this experiment the quantity of calcareous earth 

 was reduced to l-8th, and the revived metal approached to 

 within nine grains of Exp. I. 



Recap'Uulalion. 



Exp. I. Oxide and l-10?b of charcoal yielded 53 grains 



of metal,' or 9.9 per cent. 



JE.rp. II. Oxide and l-]0lh of charcoal, and 100 grains 



of chalk. 35 grains of metal, or ] J-h- percent. 



. Exp. III. Oxide and 1-lOth of charcoal, and 50 grains 



of chalk, 4 3 grains of metal, or 21-^ per cent. 



Exp. IV. Oxide and 1-lOth of charcoal, and 25 grains 



of chalk, 49 grains of metal, or 24^ per cent. 



The comparative effects of clay and sand used in a similar 



manner were proved by the following ' 



Exp. V. Oxide the same as formerly - 200 grains. 

 -Carbon 1-lOth - - - 20 

 Dried Cornwall clay - - 100 



The result was a metallic button possessed of a smooth 

 polished surface weighing 42 grains, or 21 per cent. 



This experiment was twice repeated, and the results were 

 43 grains, or 21^ per cent.; and 42 grains, or 21 per cent. 



Exp. 



