II. POWERFUL FORCE GENERATED BY PROTEIN POLYMERIZATION 47 



estimated to be so great as 20. In such a case the layer must have a 

 thickness much greater than that estimated above, and hence it seems 

 possible that even the water molecules existing at a distance even 

 greater than 900 A apart from the particle surface have a property- 

 somewhat different from that of the ordinary water. 



Estimations are made above on the assumption that the water con- 

 tent inside the particle is 70 per cent, but there are no great alterations 

 if it is assumed to be either 65 or 75 per cent : with vaccinia virus 

 particle it is calculated to be 1,100 and 800 A, respectively ; with 

 phage 350 and 270 A. 



The thickness of the water layer thus appears to vary with the 

 size of the particle in the direct proportion to the diameter. This 

 must result in the fact that the quantity of the combined water is 

 identical regardless of the particle size. 



Rothen (10) reached to a similar conclusion in his studies on the 

 "long range force" acting between an antigen and its antibody. Accord- 

 ing to him, the force becomes greater and can reach longer distances 

 as the thickness of the antigen molecule layer increases. This long 

 range force may cause the attraction of the water molecules around the 

 virus particle. Since this force is specific as claimed by Rothen, it 

 seems highly probable that viruses can act upon the host cells through 

 this long range force. If so, the action is expected to become greater 

 with the increasing particle size. This, as is argued in the following, 

 seems actually the case. 



Long range interaction seems to occur also in a solution of tobacco 

 mosaic virus, where the molecules assume regular positions at intervals 

 as great as 1,000 A (11), a finding which should be expected from the 

 existence of the thick water layer. It has been reported that even in 

 haemoglobin crystals molecular layers of the protein seem to be sepa- 

 rated by water to a distance of 65 A ; 30 per cent of the water of 

 haemoglobin crystals is so firmly bound that it is not available as a 

 solvent for small ions (12). 



Rothen (13) insists upon the existence of the long range force act- 

 ing several hundreds A between an antigen and antibody and between 

 an enzyme and its substrate, while a number of workers are disin- 

 clined to accept his view. It is, however, never an unusual pheno- 

 menon that various particles or granules in physiologically active cells 

 exert their influence on each other even when the distance between 

 them is considerably great and can take positions in a mutual connec- 

 tion. Since this seems also true in vitro observation, the writer is like- 

 wise firmly convinced of its existence. 



