OP ARTS AND SCIENCES. 



209 



The amount of gas occluded by magnesic oxide is thus far more 

 than that occluded by the oxides of copper, zinc, and nickel. The 

 quantities of carbon dioxide recorded in the table are undoubtedly far 

 from accurate, since the gas was collected over water. It is interesting 

 to note that the amount of nitrogen evolved by the oxide upon going 

 into solution was slightly increased up to a certain point by the increas- 

 ing time and heat of the ignition, while the amount of oxygen was 

 rapidly diminished. 



VOL. XXVIII. (N. S. XX.) 



14 



