100 



INFRA-RED EMISSION SPECTRA. 



Oligoclase 



3 NaAlSi a 8 ' 

 CaAkSiaOg 



(Rod 9 by 2.8 mm. Energy supplied. Curve a = 8.6, 6 = 13.3, an d = 29.4 watts. 

 Curves a and b, fig. 66. Transmission, Carnegie Publication No. 65, p. 64.) 



' The original crystal, as well as the glass rod, were perfectly transparent. 

 The rod showed no color on suddenly throwing off the current. The 

 platinum terminals melted on 16 watts, but the rod showed no color. As 

 in the preceding feldspars there are bands at 2, 2.88, 3.1, 4.1, 4.5, and 7 ;x. 

 The absorption band at 4.8 /j. seems to be shifted to 4.5 /* in the emission 

 spectrum. Curve c shows the distribution of energy when the rod (another 

 sample, plotted to a different scale) was heated until viscous, see fig. 91. 



cm 

 60 



50 



40 



> 



.52 30 



20 



10 



2 3 



Fig. 67. 



4 5 



Amphibole. 



8JU 



Amphibole (Tremolite?) [CaMg 3 (Si0 3 )4]. 



(Rod 6 by 1.5 mm. Energy supplied, 2 (?) and 4.8 watts. Curves a and b, fig. 67. 



Transmission, Carnegie Publication No. 65, p. 64.) 



At the highest energy consumption the color of the filament was a light 

 yellow, corresponding to a temperature of 1200 to 1300 . The emission 



