528 



Dr. L. Silberstein on Molecular 



The coefficients b, g, and therefore k, being known from 

 the observed refractivity of the diatomic gas, and k being 

 determined by (18), the product sb will be found by means 

 of (15). And inserting sb in (14) we shall obtain the atomic 

 coefficients b , g , and at the same time the value of s and 

 therefore also the interatomic distance It!. 



3. Hydrogen, Oxygen, and Nitrogen. 

 The coefficients for these diatomic gases, as given by their 

 observed refractivities, at least within the visible region of 

 the spectrum, are (Phil. Mag. Feb. 1917, pp. 219-221), 



Z> = 2'044 5 ; 



6 = 3-967; 

 6 = 4-409 : 



k= 



_b 2 



= 3-268 



10 10 , 



(H 2 ) 





k 



= 6-295 



. 10 10 , 



(0,) 





k- 



= 10-18 



10 10 . 



(NO 



</=l-27 9 .10- 10 

 r/=2-50 .10- 10 

 0=1-91 .10-^ 



Thus, by (16) and (18), the values of k to be attributed to 

 the atoms of hydrogen, oxygen, and nitrogen are 



k = e, 2e, 3e, 



respectively. Substituting these numbers and the above 

 numerical values of k into (15), I find, for hydrogen, oxygen, 

 and nitrogen, respectively, 



^0=0-3932, 0-4436, 0*2962, 



each satisfying abundantly the condition of stability, (19). 

 Substituting these values of sb , and the above 6's, in (14), 

 we find the required atomic coefficients b , u = \ ~*, whence 

 also s and therefore H. The atomic attributes thus obtained 

 for the three elements are collected in Table I., which, 

 besides the coefficients k and the free wave-lengths X , con- 

 tains also the critical distances R c of two equal atomic centres, 

 determined by lirRc ' = ab . 



Table I. 



Atom. 



X .10\ 



K . 



Atomic Eef'ractivity N . 



Diatomic Molecule. 



U 



a. 



H /3 



H 



y 



B.]Q 8 . 



Rc . 10 8 . 



0-895 

 1-104 

 1-175 



H... 



O ... 



N... 



710-8 



688-0 

 617-2 



6=1'83.10 10 . 

 2e 



36 



0-936 

 1-752 

 2-110 



0-945 

 1-768 

 2-125 



0-950 

 1-777 

 2-134 



1-222 

 1-448 

 1-764 



