114 



SPECTROSCOPIC INVESTIGATIONS 



material support for the attempt to attribute both the emission and 

 inactivation spectrum to the same system. 



Although the information that can be obtained from the detailed 

 form of the photochemical inactivation spectrum of Ph. phosphoreum 

 is not great, it has more weight if the additional information we have 

 about the chemical nature of bacterial luciferin is taken into account. 

 As van Schouwenburg has amply discussed (1938), bacterial luciferin 



15 



17 



19 



21 



23 



25 



27 xlO'cm- 



FiG. 11. Qualitative mirror symmetry between the emission and photochemical 

 inactivation spectra of three luminous bacteria. 



may be reversibly oxidized and reduced in the bacterium, just as was 

 demonstrated previously by Harvey for Cypridina luciferin. At the 

 time the inactivation spectrum was measured, we still believed it a 

 reasonable assumption that the various luminescent systems found in 

 nature were at least related. It is probably for this reason that we 

 have thought it permissible to take into account the results of ob- 

 servations with other organisms in making speculations about the 

 chemical nature of the compound whose inactivation spectrum had 

 been measured. 



One of the very few bits of American literature which came to us 

 during World War II was a publication by Chakravorty and Ballen- 



