96 



THE PHYSICS OF VIRUSES 



perature is, therefore, to increase the volume inactivated and 

 not to increase the sensitivity of a highly significant target 

 volume. 



These two experiments show that the simple considerations 

 advanced by Lea and used by him to deduce an internal struc- 

 ture for vaccinia cannot be applied with certainty. First, the part 

 of radiation action which seemingly inflicts damage, which can 



2 5 - 



20 



c I 5 



5 10 15 20 



Deuterons Threading Sensitive Area 



25 



Fig. 3.9. Increase in latent period of T-1 phage due to deuteron bombardment. 



accumulate to be fatal, must be ascertained and eliminated from 

 the calculations. Then the area and volume technique can be 

 used for analysis of internal structure. 



Structural Deductions 



Applying this idea to T-1 phage turns out to be rather hard 

 because the laborious experiments to determine the nontempera- 

 ture-dependent cross section at high ion density have not yet 

 been inade. The figures now available show that the measured 



