﻿238 



Prof. E. C. C. Baly oa 

 Table XIH. — Naphthalene absorption 



l/\. 



30(5 



259 



212 



165 



118 



71 



23 







23 



71 



118 



165 



212 



259 



306 



3016 



3063 



3110 



3157 



3204 



3251 



3299 



(3322) 



3345 



3393 



3440 



3487 



3536 



3581 



3628 





o 



Wave-lengths 



iii Angstroms. 



Calc. 



Obs. 



3311 





3265 





3215 



3218 



3168 



3158 



3121 



3118 



3076 





3031 



3025 



29901 



2945 J 



2907 



2868 



2828 



2793 



2757 



2965 



2867 

 2830 

 2798 

 2759 

 2670 



may be claimed that the above calculation completes the 

 evidence and confirms the theory here put forward of the 

 complex structure of ultra-violet absorption bands. 



Two interesting points may be noted, one of which is the 

 agreement of the only observed infra-red band of naphthalene 

 with the calculated value, and the other is the fundamental 

 frequency of 302. This frequency is practically the same as 

 that of o-xylene, which is 301. Naphthalene can be looked 

 upon as containing ortho substituted benzene rings, and it 

 would seem therefore as if 301 or 302 might prove to be 

 the fundamental frequency of ortho disubstituted benzene 

 compounds. 



There is no doubt that it should also be possible on the 

 present theory to explain the phosphorescence spectra as 

 observed by v. Kowalski* and by Goldstein f with certain 

 organic compounds. Both these authors investigated the 

 phosphorescence of the solid substance at very low tempera- 

 tures, and we have no knowledge of the shift of the bands 

 under these conditions as compared with the vapour. It is 

 impossible, therefore, to calculate the frequencies from these 

 authors' measurements in the way adopted above. 



The following substances may be selected, namely, benzene 

 and ^-xylene, both of which were investigated by v. Kowalski, 



* Phys. Zeit. xii. p. 950 (1911). 



t P/u/s. Zeit. xii. p. 614 (1911) ; Deutsch. Phys. Ges.,Verh. xiv. pp. 33 

 & 493 (1912). 



