118 



THE PHYSICS OF VIRUSES 



3 X 10"^'^ cm^, so this corresponds to a percent volume change of 

 6.1 X 10~^. Such a small change, seen as part of the whole virus, 

 seems too minute to be effective. It is more likely to be thought 

 of as a volume change in one sensitive molecule of molecular 



60 Minutes 



Time 



Fig. 4.7. Effect of pressure on the inactivation of T-5 according to measure- 

 ments of Foster, Jolmson, and Miller (1949). Pressure reduces bond lengths and 

 gives an increased stability. 



weight, say, 100,000 for which the volume change is about one- 

 tenth of one percent or so. 



The figures obtained by Foster, Johnson, and Miller for 

 AlP and AS^ do not agree with previou.sly quoted values obtained 

 by Adams. Whereas this may well be due to the difference in salt 



