SPECIFICITY OF LONDON-EISENSCHITZ-WANG FORCE 49 



in the most interesting macromolecules are not yet available (cf. the discussion 

 period). Before proceeding to suggest some possible biological implications 

 it may be good to recall part of the history of the ideas presented here. 



Jordan (1938, 1939, 1941, 1947) attempted an attack on this problem of 

 specific interaction of identical molecules on the basis of cjuantum-mechanical 

 resonance, and his resonance arguments received a critical analysis by Pauling 

 and Delbrueck (1940). The long range R~^ resonance attraction or repulsion, 

 depending on the symmetry of the wave function, is also mentioned in Dr. 

 Hirschfelder's paper; the present note of ours deals, however, with the disper- 

 sion force interaction (completed with contribution of excited states) which is 

 proportional to R~^. 



The investigation of the present paper had its origin in a fundamental bio- 

 physical problem (Muller, 1922, 1937, 1941, 1947). This is the problem of ex- 

 plaining why organic macromolecules or molecule complexes which represent 

 the genes "specifically" attract like molecules or complexes, discriminating with 

 great accuracy between their homologous partners and all others as exhibited 

 in inverted synapsis during meiosis. (The word 'gene' is used in this note 

 both, to refer to the genetic fine structure, i.e. to a particular nucleotide pair, 

 and also, especially in connection with this paragraph, to refer to a much 

 larger structure, i.e. a particularly folded macromolecular complex). The genes 

 have an enormous stability in their natural surroundings. Their stability can be 

 understood if one assumes them to be three dimensional compact structures 

 with many stabilizing internal cross links which guarantee the restitution of 

 their structures if some bond happens to get broken. A well-defined intermolec- 

 ular structure would then be expected to correspond (in the oscillator model) 

 to a very definite set of oscillator frequencies, as regards the electrical oscilla- 

 tions. Not only these frequencies but also the directions in space of the aniso- 

 tropic oscillator moments are expected to be determined by the structure. 

 This line of thought suggested the investigation of possible specificity effects 

 of the London-van der Waals interaction. 



The present investigation was based on a model which represented the mole- 

 cules or complexes as compact well-defined structures equivalent to a set of 

 electrical oscillators, and assumed the molecules or complexes to carry ap- 

 preciable electric charges and to be imbedded in an ionic medium. Electrostatic 

 forces between identical macromolecules (which, as concerns the effect of their 

 identical net charges, repel each other) can be regulated by concentration 

 changes of the ionic composition of the medium in which they are suspended. 

 The interplay between these controllable repulsive forces and highly specific 

 London-Eisenschitz-Wang attractive forces could provide a mechanism for 

 various biochemical processes. The motion of chromosomes in meiosis might 

 perhaps illustrate such an interplay. It might be that changes in the medium's 

 ionic composition allow the chromosomes to come together or to be forced 

 apart. 



