JBroivrdng and Russ. 



Roy. Soc. Proc, B, vol. 90, PI. 3. 



Wav e - Lengths 



2940 



Time of 

 exposure 



2600 

 1 

 I 



2380 A.U. 



6 minutes. 



12 



24 



Fig. 1. 



<-VisiBLE-^i^ Ultra-Violet Region of Spectrum 



\ I : ; Wave- | 



Green \ ; i ; Length ' 



3800 2960 2480 2250 A.U. 



Tungsten / 

 Spectrum 



Bacterial 

 ftltn exposed 

 to whole 

 radicLtion; 

 then 



incubcLted 



Absorption 

 Spectrum \ 

 of Bacteria.' 



Fig. 2. 



