256 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Temperature. 



1433 

 1420 



1448 



It is evident that, though the reaction goes in both directions at this 

 temperature, it is so slow that it is difficult to tell whether an equi- 

 librium has been reached or not. The reason for this may have been 

 that the charge had become very hard and could not be dug out of the 

 crucible, and appeared as though it had been somewhat fused together. 

 This would make it difficult for the nitrogen to penetrate its entire 

 mass. The average temperature of this run was 1437°. A later 

 attempt at 1448° was more successful, and is given in Experiment 15. 



