Oxides of Cation and Iron. 237 



pftper and mixture were with facility introduced into the 

 crucibles respectively, and the immediate introduction of 

 the cover prevented the most minute contact of air, or dis- 

 sipalion of the subject of experiment. The duration of the 

 crucible and degree and management of the heat in the 

 furnace were scrupulously attended to, and many of the ex- 

 periments were repeated three times. 



The first class of experiments was with various woods, 

 from which the following were selected : 



Experiment I. 

 Charcoal prepared from Walnut, composed cf 

 Oxide of carbon - 96*048 

 Ashes - - - 3* <J52 



100 parts, 



15 grains of this oxide and 200 grains of oxide of iron, 

 were subjected to fusion, after being carefully mixed, and 

 the result was a metallic button which weighed 36 grains, 

 (equal to 18 per cent.) from the oxide of iron. 



It was found, upon a calculation of what this wood lost in 

 distilling, that 76 grains of raw wood would have- formed 

 15 grains of the charcoal operated upon. This quantity of 

 wood was therefore rasped dowrr, and, in a similar manner 

 with the former, introduced into the crucible. The result was 

 A metallic button weighing - 49 grains. 



Charcoal of the same wood, revived as above, 36 

 Increase (equal to 6| per cent, or 24} upon 

 the whole,) - - - - - 13 



Experhntnt II. 

 Charcoal prepared from Elm, composed of 

 Oxide of carbon - 96*70 

 Ashes - - - 3-30 



100 parts, 



15 grains of oxide from elm and 500 grains of oxide of 

 iron, yielded a metallic button weighing 40 grains (equal to 

 20 per cent.). 

 »* . 75 grains 



