802 Dr. It. D. Kleeman on the Nature of tlie 



Now the value of the right-hand side of the equation will 

 not be altered if we place the integral sign before the 

 summation signs, the equation then reducing to 



2 m 4 \m) \ „=_«,«=-«> »=i {«0 s 4-u 2 + » 2 } 2 



+ 4 2 2 , ,\_ 2 , 2 +4 2 ^K 

 r=i «=i {w 2 + v 2 ^ 2 w=1 r 4 J 



From this equation K can be determined. The value of the 

 summation quantity obtained by expanding it in series and 

 adding together the most important terms is within a few 

 per cent, equal to 8*93. The value of L must be expressed 

 in ergs, and for m the absolute mass of the molecule must be 

 substituted, the value of nix in 2 \A>*i is, however, the atomic 

 weight in terms of that of the hydrogen atom taken 

 as unity. The absolute mass of a hydrogen atom will be 

 taken as 7*1 X 10~ 25 grm. The calculation was carried out 

 for ether and carbon tetrachloride at § T c . For ether the 

 equation becomes 



75-4 x 4-2 xlO 7 K (27-8) 2 (- fi907)^ 



2 ~~ ~ 4 (7-lxlO- 25 x74)^ Xb " J °' 



which makes K equal to 1*55 x 10~ 46 . In the case of carbon 

 tetrachloride we have 



39-87 x 4-2 x 1 7 __ K (27-3) 2 (l/4385) 4 / 3 



2 ~ 4 (7 T 1 x 10- 25 x 154) 7 * X b * yJ ' 



or K=l-77xl0" 46 . 



The value of K may thus be taken as 



2 x 10- 46 (gram)(cm.)(sec.)- 2 



in round numbers. It will be observed that K is the chemical 

 attraction between two atoms of hydrogen separated by one 

 centimetre. 



It will be interesting to compare this force of attraction 

 with that due to gravitation. Two masses each equal to one 

 gram and separated by a distance of one centimetre attract 

 one another with a force equal to 6'6579 x 10~ 8 dyne. The 

 gravitational attraction of two hydrogen atoms on one 

 another unit distance apart is therefore 3356 X 10 -56 dyne. 

 A comparison of this value with that of K shows that the 

 chemical attraction is greater than the gravitational for dis- 

 tances less than 100 cm. from the attracting body. But 

 this cannot be true since the gravitational force has been 



