Dispersion in Relation to the Electron Theory. 



461 



The expression for p obtained from natural dispersion 

 contains e/m, but it will bo noticed that this quantity is- 

 eliminated in the present calculation. 



The values of p for some typical organic substances 

 calculated from equations (10) or (11) are given in Table III., 

 a and f being in all cases neglected. Normal values of v 

 onlv are given. 



Table III. 



Substance. 



v. 



P D - 



D^W 



p x (inin.). 



Water 



4 

 8 

 10 

 16 

 22 

 34 

 14 

 20 

 20 

 10 

 16 

 22 

 28 

 34 

 46 

 22 

 28 

 34 

 38 



1 

 3-3 



•989 



1-64 



2-78 

 3-768 



2-385 

 3-332 

 3-514 

 1-671 

 2-525 

 3-462 

 4-472 

 5-513 

 7-552 

 3362 

 4-462 

 5-487 

 6-670 



3-4 

 12-5 



io-o 



14-6 

 20-5 

 31-0 

 13-6 

 191 

 18-3 

 11-0 

 16-7 

 22-3 

 27-9 

 33-4 

 44-5 

 24*2 

 27-7 

 33-4 

 335 



Carbon bisulphide 



Methyl alcohol 



Ethyl alcohol .. 



n. Propyl alcohol 



Arnyl alcohol 



Acetaldehyde 



Propaldebyde 



Acetone 



Formic acid 



Acetic acid 



Propionic acid 





Valerianic acid 



(Enanthylic acid 



Methyl acetate 



Ethyl acetate 











30 

 42 

 64 

 92 



58 

 52 

 52 



2-305 

 1-989 

 2-560 

 2-770 

 2-940 

 2-316 

 2-869 





16-6 

 27-3 

 33-2 

 49-5 

 29-7 

 29-6 

 25-9 





Diphenylmethane 



Diphenyl 



Dimethylorthotoluidine ... 

 Dimethylparatoluidine . . . 





44 

 46 

 44 

 46 

 40 

 62 

 62 

 58 

 38 

 64 

 48 



2-448 

 2-040 

 2-208 

 2-095 

 2-428 

 3-588 

 3-336 

 1-914 

 3-576 

 5-144 

 3-826 





27-8 

 30-1 

 26-2 

 29-4 

 22-3 

 277 

 28-5 

 40 9 

 18-7 

 23-2 

 27-1 



Hydr indene 



Orthotolylmethyloxide . . . 

 Dimethylresorcinol 





a-naphtbylethvloxide 



0- ... ". « 



m. Phenylenediamine 



a-monobromnaphthalin ... 



A comparison of the columns v and p shows that probably 

 in every case the number of electrons influencing the 

 refraction is not greater than the total number of normal 

 valencies of the atoms. 



