﻿Liqlit Absorption and Fluorescence. 



227 



series of absorption lines, each series starting from the 

 central line. There would be pairs of arithmetical series, 



Table II. — Benzene absorption (Hartley). 



X in 









Infra-red bands. 



Angstroms. 



1/X. 



v x . 



Mean v x . 



^ , 1 













Calc. 1 



Obs. 



2687 



3722 



333 



333 



3-00 fi 





A 2670 



3745 



310 





3-23 



3-25// 



i A 2630 



3802 



253 



248-5 



402 





2612 



3828 



227 



228 



4-38 



4-40 



2600 



3847 



208 



208 



4-80 



4-90 



A 2590 



3861 



194 



194 



5-15 





2582 



3873 



182 



182 



5-50 



5-41 



2567 



3895 



160 



160 



623 



6-20 



2560 



3907 



148 



148 



! 675 



6-75 



2553 



3917 



138 



138 



725 



7-22 



2546 



3928 



127 



127 



' 7-85 



7-80 



2538 



3940 



115 



115 



\ 8-67 



8-67 



2529 



3954 



101 



101-5 



9-85 



9-78 



2527 



3958 



97 



97 



10-30 



10-30 



A 2523 



3963 



92 



92-5 



1081 



10-78 



2519 



3970 



85 



85 



11-80 



11-80 



2516 



3974 



81 



81 



12 30 



12-45 



2514 



3978 



77 



77 



1295 



12-95 



A 2466 



4055 













2420 



4132 



77 



77 



j 12-95 



12-95 ' 



2417 



4136 



81 



81 



| 1230 



12-45 



2416 



4140 



85 



85 



11-80 



11-80 



A 2411 



4148 



93 



92-5 



10-81 



10 78 



2409 



4152 



97 



97 



10-30 



10-30 



2406 



4157 



102 



101-5 



9-85 



9-75 



2398 



4170 



115 



115 



8-67 



8-67 



2391 



418-: 



127 



127 



7-85 



7-80 | 



2385 



4 i93 



138 



138 



, 7-25 



725 



2379 



4203 



148 



148 



i 6 - 75 



(no 



2373 



4215 



160 



160 



: 6-23 



6-20 



A 2360 



4237 



182 



182 



! 5-50 



5-50 



2354 



4249 



194 



194 



! 5-15 





2346 



4263 



208 



208 



! 4-80 



4-90 



2334 



4284 



229 



228 



4-3S 



440 



A 2326 



4299 



244 



248-5 



4 02 





| A 2279 



1 



438S 



333 



333 



3-00 





one on each side of the central line, and the result would be 

 the appearance of heads which mark the regions where 

 several lines of the different series happen to fall together. 

 On this explanation the heads will have no especial signifi- 

 cance in the present connexion, and so will not necessarily 

 be expected to correspond to bands in the short-wave infra- 

 red region. It is possible that in this combination of the 

 three vibrations electronic, atomic, and molecular (rotational), 

 the explanation is to be found of the structure of all band 



Q2 



