Action of Radiations on Viruses 



157 



10'^ I0-* J0"3 I0-'* 10-^ I0"2 IQ-' 



FIG 1. Inactivation of Viruses in Aqueous Suspension by X-rays 



Abscissae == concentration of solution in grams per milliliter, 

 Ordinates = inactivation doses in rontgens. 



A. Tobacco mosaic virus.^^ 



B. Shope rabbit papilloma virus.* 



(Reproduced by permission of the ^Cambridge University Press) 



Macromoleciilar Viruses 



The study of the direct inactivation of viruses has so far yielded 



results of greater interest than the study of the indirect action, 



* and we, therefore, confine our subsequent discussion to the direct 



action. If, on the basis of the results of chemical experiments 



already mentioned, we are prepared to accept that, in the cases 



