different Earths for Carton. 343 



duce with this small proportion of carbon 7-^ths per cent. 

 The glass obtained was of a rusty yellow colour mixed with 

 black veins : the surface covered with brown vitrified oxide. 



IV. 500 grains of mixture, 



25 of charcoal, or l-20th. 



This mixture had fused in a very perfect manner, and a 

 beautiful metallic spherule obtained which weighed 45 

 grains; equal to 9 per cent. The quality was malleable 

 iron as soft as copper. The glass was a curious heteroge- 

 neous mixture of yellow and vitrified sand. In cooling, a 

 complete separation of the parts had taken place. The iron 

 was found beneath the yellow glass, but a mixture of sili- 

 ceous particles and oxide had formed a handsome cone over 

 all about one inch in height. 



V. 500 grains of mixture, 



33 of charcoal, or 1-1 5th nearly. 



The fusion of tl*is mixture yielded a button of smooth- 

 skinned malleable iron which weighed 65 grains ; equal in 

 point of produce to 13 percent. The mass of glass was 

 light shining yellow, surmounted by a thin stratum of oxide 

 of a purple brownish colour. 



This experiment was repeated, and a metallic button ob- 

 tained which weighed 63 grains, or lS^ths per cent. The 

 result otherwise was the same. 



VI. 500 grains of mixture, 



50 of charcoal, or l-10th. 



This mixture was found unfused in a heat of I6o°of 

 Wedgewood. The particles of quartz remained pure as 

 when first introduced, but considerably rounded by the ac- 

 tion of the oxide. The latter had resolved itself into a dark 

 yellow glass, which had penetrated in small veins the mass 

 of some vitrified sand. 



Three detached masses of iron were found which weighed 

 45 grains ; or 9 per cent. This experiment was repeated at 

 a higher heat, and apparently a greater quantity of iron was 

 revived; but this was dispersed over the surface of the un- 

 fused matter in thousands of minute silvery globules. What 

 could be collected weighed 62 grains ; equal to 1 2 T 4 ths per 

 cent. 



VII. 500 grains of mixture, 



80 of chalk, 



50 of charcoal, or 1 - 1 0th the mixture. 



The result of the exposure of this mixture in a tempera* 

 ture similar to the former was a complete fusion, a very per- 

 fect mass of greenish glass, and a neat metallic button which 

 weighed 101 grains; equal to 20 T ^ths per cent. 



A a 2 By 



