340 On the Jffimties of 



rounded the iron. Its surface, however, was covered with 

 a deep crocus-coloured film striated with milky blue lines. 

 In the former experiment a fraction more than a grain 

 of metal was obtained for each grain of charcoal ; in the 

 present nearly 2 grains of soft malleable iron were obtained. 



III. 500 grains of mixture, 



33-J of carbon, or l-15th. 



There resulted from the fusion of this mixture a very per- 

 fect button of malleable iron, which was found to weigh 63 

 grains: produce in metal equal to 12^ (y ths per cent. The 

 glass in this experiment was less black and shining than in 

 former, inclining to clear brown somewhat transparent. A 

 few globules of metal had evidently deflagrated upon the 

 surface of the glass. 



IV. 500 grains of mixture, 



42 , or nearly 1 - 1 2th carbon. 



This mixture was exposed to a very high heat. The cru- 

 cible was shapeless when taken from the furnace, but the 

 contents were safe. The fusion was imperfect. The clay 

 and charcoal evidently form with the oxide a mixture very 

 infusible, of a rough spongy nature, full of bright globules 

 of metal. 



A mass of malleable iron was found which weighed 77 

 grains, equal to 15-j*jths per cent. 



V. 500 grains of mixture, 



50 of charcoal, or l-10th. 



This proportion was exposed to a similar heat with 

 former, but was found to possess less evident marks of 

 fusion. One small globule of iron only was found sepa- 

 rated. 



VI. 500 grains of mixture, 



70 , or nearly 1-Jth' of charcoal. 



This mixture, after a similar exposure, was also found 

 tin fused. A number of minute silver-coloured globules 

 had exuded from the surface of the agglutinated mixture, 

 and a few were found carburatcd upon the surface. 



It would appear therefore to result from these experi- 

 ments, that clay alone, as a mixture, is unfavourable to the 

 operation of iron, seeing that the largest collected produce 

 did not exceed 15-Aths per cent, (see Exp. IV.) ; whereas 

 the proportion of iron contained in the oxide, had it been 

 entirely revived, would have amounted to at least 28 per 

 cent. 



To prove that the oxide contained no matter capable of 

 reviving iron, nor the clay which was mixed along with it, 

 I took 



3 VII. 300 



