tHspersion of Fluorbenzehe and Allied Compounds. 3 





Temp. 

 C. 



57-68 

 57-62 

 57-60 

 67-45 



R D . 



»r 



R H . 



Broinobenzene 



o 



1-5 

 23-3 

 300 



7'0 



58-76 

 69-06 



70-98 



62-83 



62-81 

 62-72 

 74-58 







Iodobeuzene 





These figures are almost identical with those determined 

 from Dr. Young's specimens. They not only increase our 

 confidence in the accuracy of the data, but the experiment 

 with bromobenzene shows that we may practically disregard 

 the question of temperature. 



Adopting the data in the first two tables, we can estimate 

 the molecular refraction of each halogen in combination by 

 deducting the value for C 6 H 5 . This has been arrived at by 

 taking the average refraction of several good specimens of 

 benzene for the six lines, and by subtracting from them the 

 assumed value for hydrogen. 





*v 



R c . 



R D . 



R F . 



R G . 



R H . 



C B H 6 ... 

 H ... 



J 43-59 

 .. 1-30 



4401 

 1-31 



44-48 

 1-31 



45-52 

 1-32 



46-50 

 1-33 



47-39 

 1-34 



C G H 5 ... 



.. 42-29 



42-70 



43-17 



44-20 



45-17 



46-05 



Deducting these figures from the values given in the second 

 Table, we obtain those of fluorine, chlorine, bromine, and 

 iodine for the several lines : — 





%■ 



R c . 



R D - 



R . 



R G . 



R H . 



Fluorine 



0-63 



0-63 



0-53 



0-48 



0-44 



0-35 



Chlorine 



10-00 



10-09 



1011 



1032 



1052 



10-70 



Bromine 



15-23 



15-20 



15 48 



1591 



16-31 



16-64 



Iodine 



25-20 



25-57 



25-91 



26-85 



27-70 



28-63 





B2 



