62 



INFRA-RED REFLECTION SPECTRA. 



maximum is not sharp and well denned, several readings were made and 

 plotted in the figures. This method of reading a flat band establishes a 

 limit within which the maximum may lie. The two graphs are approxi- 

 mately parallel, and show a uniform shift of the maxima of Mg, at 6.55 

 and 6.86 ft to 6.94 \i and 7.18 fi, respectively, in Pb. The carbonates of Fe 



6.4 6.6 6.8 7.0 



11.4 ll.b 11.8/1- 14.0 14.2 14.4 14.6 14.8 l5jU 



Fig. 43. Maxima of reflection bands of carbonates. 



and Cu lie farthest from the curves; but they belong to a different group 

 in Mendelejeff's table. The graphs at n /< and 14 p. are due to Morse, 

 see Appendix III. 



In fig. 44 are plotted the maxima of the reflection bands of the sulphates 

 [(H 2 , Mg, Ca, Sr, Ba)S0 4 ], previously examined (Part IV). Here there are 



160 



140 



I2Q 



I 



y 80, 



' 



o 



< 60 



40 



20 



6.2 8.3 8.4 8.S 



Fig. 44. 



.6 8.7 8.8 Q.9 9.0 9.1 9.2 9.3 9.4 9.5 9-6 9.7JU 

 Maxima of reflection bands of sulphates. 



