1255 
Further that in the fifth series He — 11,0. Hence we have for the 
six horizontal principal series of the periodic system resp. the 
fundamental values (with He == 1 in the series zero) 
ies OT 9; and A WOOS), 
so that Ya is exactly 2 units greater in every successive horizontal 
series. 
We may still remark that the proportion of the fundamental values 
of hj. of the last members in the first four horizontal series (of the 
halogen group) is exactly as: 
ioe ee co = tk, 
a) For the application of the fundamental table fora, we should 
further bear in mind that the atoms C,Ge,Sn,N, and P hare no 
part in the attraction, when (as in CH,,CHCI,,CCl,,C,H, ete.; 
GeCl,, SnCl,; NH,, PH,) they are surrounded symmetrically on a// sides 
by other atoms (or atom groups) which absorb the lines of force. 
6) Wherever a carbon atom exhibits double bindings (C,H,, i-C,H,,, 
C,H,, C,H,S) © must be taken = 1,55, and for’ triple binding 
(C,H,) C=3,1. The same full value 3,1 also oceurs in CO, CO,, 
CS, ete., just as in the group CO of the ketones, organic acids and 
compound esters. 
c) Finally with regard to hydrogen, the fu// value 3,2 is found 
for all anorganic compounds (except H,S and H,Se) and in the group 
OH of the alcohols and organic acids; whereas Malf the value 1,6 
is found for H,S, H,Se and for a/l organic compounds, where H 
is directly bound to C. 
Physics. — “On the Validity of Matunws’ so-called Valency Law.” 
By Dr. J. J. van Laar. (Communicated by Prof. H. A. Lorentz). 
(Communicated in the meeting of January 29, 1916). 
It now remains to say something about fhe so-called rule of 
Marturws') that namely a would be = C(M x vj, hence Va = 
=WCM xv)’, when M represents the molecular weight, and » 
the total number of effective valencies. Thus e.g. for n-C,H,, J/= 72, 
Pri box 412 KAD hence BTA x32) 19,2 tand 
— 19,7 Xx 10-2: 13,2 = 1,49 x 10-2. And for C,H,C]l M=112,5, 
r=6 X¢+5x1+1 x 1=830, hence Bb (112,5 x 30) = 15,0) and 
VC= 22,8 Xx 10-2: 15,0 =1,52 « 10-2, which is almost equal to 
daal. 
1) Journal of Physical Chemistry, 1913 (nine articles). 
SO 
Proceedings Royal Acad. Amsterdam. Vol. XVIII. 
