32 INFRA-RED TRANSMISSION SPECTRA. 



common with water. Evidently this needed further investigation; 

 and this was done with minerals purchased from various dealers, care 

 being taken to obtain them from different localities. Curves b and 

 c give the transmission for transparent yellow crystals, t=o.^ and 

 0.15 mm. respectively, which came from Arten, Thuringia. Curve d 

 is the transmission for a grayish-white translucent crystal, ground to 

 0.12 mm. in thickness, from Mallonka, Austria. Curve e is for a white 

 transparent crystal, 0.06 mm. in thickness, from Tula, Russia. In all 

 these curves it will be noticed there is no energy transmitted beyond 



10 



345678 

 FIG. 17. Cassiterite (a) ; Mellite. 



10 



3/i, while from the very nature of the transmission curves the 1.5 band 

 is invisible and the 2 /* band is almost obliterated. As a whole the 

 theory that, in crystal-water, the bonding is the same as in ordinary 

 water has also been confirmed with mellite. A letter of inquiry to 

 Steeg and Renter in regard to the sample sent us revealed the fact 

 that cassiterite (SnCX) was accidentally substituted for mellite. The 

 fact that it was possible to detect the error would indicate that the 

 method of analysis is trustworthy, and in that respect it is fortunate that 

 the substitution occurred. 



