474 LIGHT AND LIFE 



and let me sus^srest that small pressure apparatuses are now very cheap. 

 One can make a little hand pump machine with a little bomb which you 

 can set on your laboratory talile and get something of the order of a 

 thousand atmospheres. Now, it is always something of a surprise to a physicist 

 that biological creatures sur\'ive at the bottom of the sea where the pres- 

 sures are so high. It is clear that biological systems are less sensitive to 

 pressure than you might suppose. Perhaps you require mutation or perhaps 

 you recjuire adaptation, I don't know. Nevertheless, it seems to me possible 

 that for a great number of systems that you work with, especially the smaller 

 ones, one-celled systems, chromatophores, it might be possible by pressure 

 to push them into configurations which would change somewhat the dis- 

 tribution of products light performance. In particular, it will shift absorp- 

 tion spectra in the same way that temperature will shift absorption spectra. 

 I think sometimes the little bombs with sapphire windows on them to look 

 through may be simpler in fact than a low-temperature apparatus. I would 

 like to urge the use of more high pressure experiments, and the examina- 

 tion of spectra for these interactions between pigments and for different 

 pigment effects to try to isolate different electronic transitions and different 

 pigments, let me say, particularly in these cytochrome problems. 



