CALCIUM CARBONATE. 



123 



metals. Here the emission is actually suppressed, and we have an emission 

 minimum instead of a maximum, as will be described in the following 

 chapter. In the remaining part of the spectrum the emission is propor- 



345 



Fig. 02. Calcite. 



tional to the absorption. The emission bands at 2, 2.7, 3.5, 3.9, 4.7, and 

 5.5 /j. coincide with the absorption bands previously observed. The ap- 

 parent maximum at 7.3 // is due to the suppression of the radiation at 

 6.8 p. This fact can, of course, only be determined from a knowledge of 



