Laws of Molecular Force, 15 



F for the halogens in harmony with those already found. 

 Accordingly we could adopt for F for the halogens in inorganic 

 compounds the values found in the organic, but it seems to 

 me preferable to work out the results for inorganic compounds 

 on their own basis. To do so we need the atomic volume of 

 fluorine F. Now from the studies made by many chemists 

 on the molecular domains (so-called volumes) of liquids at 

 their boiling-points there have been found values carried 

 by the individual atoms into the molecule, and for the halogens 

 Thorpe (Journ. Chem. Soc. 1880) gives the values F = 9'2, 

 CI = 22 "7, Br = 28*1, and I = 36*6, whence for comparison 

 with our series of differences for the solid state we get 

 Cl-F = 13-5, Br-F = 18-9, and I-F = 27-4, which is 

 curiously close to identity with our series, and indicates that 

 we may take 9 as the atomic volume of F, so that with 

 Clarke's differences given above we have in round numbers 

 the following atomic volumes: — F = 9, Cl = 19, Br = 26, and 

 1 = 36, to be compared with the former Cl = 19, Br = 24*5, 

 and 1 = 32 (Table V.). Accordingly the part contributed by 

 the fluorine atom to (M 2 Z)* is about *9 ; and with the series of 

 differences given above we have the series of parts carried by 

 the halogen atoms into (M 2 /)*, namely : — 



F=-9, Cl=2-1, Br = 2-7, and 1 = 3-6 

 to be compared with 



Cl=2-2, Br = 2'5, and I=3'2 in Table V. 



With the above atomic volumes of the halogens and Clarke's 

 molecular volumes of the K and Na haloid compounds given 

 later on in Table XIII., we get the following mean atomic 

 volumes, Na = 7*4 and K=18'6 ; and with the above values 

 of F for the halogens, we get from Table IX. that the mean 

 value of F for Na is 3*1 and for K is 4*2. With these values 

 of atomic volume and F for Na and K, we can derive from 

 Tables IX. and X. the volumes of a number of negative 

 radicals and their values of F when they are monobasic, of 

 F/2 when dibasic, and of F/4 when tetrabasic. These are 

 given in the next table. 











Table XI. 













N0 3 . 





N0 2 . 



CN. 



oio,. 



Br0 3 . 



B 





31 (32) 





25-5 (24-5) 



25 (19-5) 



35 



33 



F 





3-7 (32) 





3-1 (2*8) 



2-7 (2-4) 



36 



37 





co 3 . 



S0 4 . 



Cr0 4 . 



Cr a 7 . 0r 3 O 10 . 



B 4 7 . W0 4 . 



P 2 6 



PA. 



B .. 



. 26 



34 



36 



76 112 



70 42 



67 



75 



F/2 



3-3 



4-0 



3-8 



6-8 99 



7-2 47 



6-7 



F/4 41 



