94 Dr. L. Silberstein on Molecular 



molecular refractivities with the observed ones, we have to 

 remember that the atomic weights are those more recently 

 adopted, viz., 16 for oxygen, 1*008 for H, and so on. 



Group CH 2 



Carbon 



Hydrogen 



hydroxy 1-Oxygen 



ether-Oxygen 



carbonyl-Oxygen 



Chlorine 



Bromine 



Iodine 



Ethylene bond [double] .... 

 Acetbylene bond [triple] .... 

 Nitrogen in primary amines 



,, in secondary amines 



„ in tertiary amines. . . 



„ in imides (tert.) ... 



„ innitriles 



Symbol. 



Ha. 



D. 



Hp- 



Hy. 



H£_Ha. 



Hy— Ha. 



CH 2 



4-598 



4-618 



4-668 



4710 



•071 



•113 



C 



2-413 



2-418 



2-438 



2-466 



025 



•056 



H 



1-092 



rioo 



1-115 



1-122 



•023 



•029 



0' 



1-522 



1-525 



1-531 



1-541 



•006 



•015 



o< 



1-639 



1-643 



1-649 



1-662 



•012 



•019 



0" 



2489 



2-211 



2-247 



2-267 



•057 



•078 



CI 



5-933 



5-967 



6043 



6101 



•107 



•168 



Br 



8-803 



8-865 



8-999 



9-152 



•211 



•340 



I 



13-757 



13-900 



14-224 



14-521 



•482 



•775 



|= 



1-686 



1-733 



1-824 



1-893 



•138 



•200 



| = 



2-328 



2-398 



2-506 



2-538 



•139 



•171 



H 2 N_ C 



2-309 



2-322 



2-368 



2-397 



•059 



•086 



hN-( C ) 9 



2-478 



2-502 



2-561 



2-605 



•086 



•119 



N-(c) 3 



2-808 



2-840 



2-940 



3 000 



•133 



•186 



c-N=o 



3-740 



3-776 



3-877 



3-962 



•139 



•220 



N=c 



3-102 



3-118 



3-155 3-173 



•052 



•060 



Let us now test the above figures, whatever tliair orig : 

 on some concrete examples, retaining in the final results but 

 two decimal figures. 



Water. 



(Hy). 



2'24 4 

 1-54! 



3-78 5 



3-78 



This can be looked upon us a very good agreement. 

 Chloroform, 



c 



(Ha). 



2'41 3 



(Hy). 



2-46 6 



H 



1*09 2 



1-12, 



3C1 



17'79 9 



18'30 3 



J -' cale. 



= 21-30 



21-89 



iVobs. 



= 21-31 





This again speaks in favour of pure additivity. Notice that 

 thus far we have had no extra-terms. The case is different 



