301 
In consequence of the provisional assumption that the attraction 
of the isolated atoms amounts here to about 30.102 (which is not 
quite certain, as no experiments have as yet taken place with atomic 
Br and 1), the values of a, and » calculated for Br, and I,, are 
accurate only in approximation. 
II. The oxygen group. 
a. Oxygen. For y 0,813 has been experimentally found (Maruras 
and KAMERLINGH Onnrs)'). From this follows for the density at the 
triple point 54°,7 abs. (K. O. and Crommeniy), where 1, — 0.3546: 
D, =1,2747 + 0,4299 x 1,626 (0,4065 -— 0,3546) = 1,311. 
At 62°,7 the density D (m=: 0,4065) is namely = 1,2746, D' being 
— 0,0001 (M. and K. O.) .Further Dz = 0,4299 (Ibid), 7, = 154°,25 
abs. (K. O., Dorsman and Horst, 1915, who also determined Vr 
while K. O. and Braak determined 7’). 
We find for the factor f,: 
; 0,813 
A 1,626 | 1 — 
3 4 0.8640 | = 1,626 (1 — 0,259) = 1,367. 
Hence bj, = 74,4.10-* follows from v, = 54,45. 10-5, whereas 
71.10 5 has been found directly from 7). and Phe 
Now the product fu, becomes: 
bnn li901 2.820 = 385, 
’ 
b. Sulphur. In 1888 Vicrentint and Omoper found the value 
1,8114 for the density at the melting point of the metastable rhombic 
sulphur (112°,8 C.). The melting point of monoclinic sulphur lying 
at 119°,25 (just as tbe preceding value given by Kruyt, Thesis for 
the Doctorate 1908; or at 118°,95 given by Wiganp, 1911), we can 
by approximation determine the density of monoclinic sulphur at 
the melting point by the aid of the cubie coefficient of expansion 
of liquid sulphur (0,000458 between 126° and 167° C. according to 
Kopp). We then find 1,8063. 
For the coefficient of direction of the straight diameter we calcu- 
late from 7; = + 700° C.=— 973° abs. the approximate value 
= 4180: 7 =— 1,093. 
This gives for the factor f, (m, — 0,403): 
1,093 
fg ote te SS 0,408 | — 2,185 (1 — 0,210) = 1,735. 
2,093 
As v, = 79,24.10-5, bj becomes — 136,7. 10-5, 125 . 10 havine 
1) With 7% = 154°,25 the formula for 24 would have yielded the value 1,4720, 
from which 7 = 0,736 would follow, i.e. much smaller than M. and K. O. found. 
