MISCELLANEOUS COMPOUNDS. 



57 



to find a shift of the maximum toward the longer wave-lengths, as we 

 increase the atomic weight of the element which is attached to the 

 radical. 



MISCELLANEOUS COMPOUNDS. 



POTASSIUM BICHROMATE (K 2 CrO 7 ). 

 (Cleavage parallel to m; ^ = 0.85 mm. Fig. 43.) 



It was found that this substance furnished beautiful, highly polished 

 cleavage pieces, which are quite transparent to infra-red radiation. The 

 curve shows a complex depression at 2.9 to 3.2 /*, and bands at 5.4, 6, 

 6.65, 7.7, and 8.7 /*. 



Porter 1 located a reflection band at 10.3 p. 



70% 



60 



50 





IV 



34567 

 KIG. 43. Potassium dichromate. 



SO/A 



POTASSIUM CHLORATE (KClO 8 ). 

 (Large transparent crystal; t = 0.47 mm. Curve a, fig. 44.) 



The absorption bands in this substance are strikingly similar to those 

 of potassium dichromate, especially the 5.25 ^ band, which is shifted to 

 5.4 p. in the latter. There are bands at 3.2, 3.5, 5.25, 6.28, 6.93, and 

 8.1 /t, beyond which there is complete opacity. 



1 Porter : Astrophys. Jour., 22, p. 229, 1905. 



