THOMPSON AND LOMBARD. — NITROGEN IN CALCIUM CYANAMIDE. 2G1 



Current in 

 Time. Kilowatts. Pressure. Wanner Temperature. 



Pyrometer. 



10.22 A. M. 10.9 4G5. 



11.00 " 10.9 449.0 



11.30 " 10.9 448.0 6.1 1448 



Absorption had taken place and the pressure had become constant. 

 Nitrogen was then pumped out. 



12.10 p.m. 10.9 430.5 

 12.30 " 10.9 433.5 6.1 1451 



2.40 " 10.9 438.0 



The pressure had become constant. Nitrogen was again admitted 

 to see if the pressure would again diminish to 449. 



2.43 p.m. 10.9 476.0 

 3.00 " 10.9 469.8 



3.15 " 10.9 471.2 6.1 1445 



It did not reach 449 but stopped at 470. On admitting more ni- 

 trogen, very little absorption took place, as seen below. 



3.50 p. M. 10.9 496.3 

 4.15 " 10.9 495.7 



4.30 " 10.9 494.5 



This run may be summed up as follows : absorption took place from 

 465 to 449 millimeters, but when pumped out to 430.5 millimeters, 

 the pressure increased to only 438 millimeters. After this the pressure 

 remained constant at nearly any value. This may have been because 

 the charge was changed by heating into a hard, solid mass, thus re- 

 ducing the surface in contact with the nitrogen. This would explain 

 why the reaction took place with a noticeable velocity only during the 

 first part of the experiment. 



The average of 449 and 438 is 444 millimeters, and the average 

 temperature is 1448°C. 



Experiment 16. 



The charge in this experiment consisted of 21.5 grams of calcium 

 carbide. 



