THOMPSON AND LOMBARD. — NITROGEN IN CALCIUM CYANAMIDE. 255 



The results of this experiment are somewhat inconsistent, as the 

 pressure was decreasing at 305 and increasing at 310 millimeters. The 

 mean of these is 308 millimeters, and the mean temperature was 

 1297° C. The current in the lamp of the Wanner pyrometer was from 

 6.3 to 6.5 units. 



It is seen that the pressure decreased until it became constant at 

 about 376 millimeters, and after pumping out to 367 it increased to 

 379. The average mean is 378 millimeters, and the average temper- 

 ature 1378° C. 



The interior of the furnace after these runs was found covered with 

 a thick white deposit. 



The charge in the crucible gave tests in each case for carbide and 

 calcium cyanamide. The latter was tested for by adding ammonia and 

 silver nitrate, which, with cyanamide, give a yellow precipitate of sil- 

 ver cyanamide. The white powder taken from the walls of the furnace 

 also gave the yellow precipitate on adding ammonia and silver nitrate 

 to a solution of this substance. 



Experiment 9. 



In this run an attempt was made to measure an equilibrium at about 

 1440°. It was not successful, however, as will be seen from the fol- 

 lowing results. 



