SULPHUR BACTERIA 



infra-red - 



Thus the point of maximum absorption is at wave-length 

 85 in the infra-red, which is beyond the end of the visible 



100 

 90^- 



80 



GO 



50- 



40|- 



30 



20 



10 



. I I I I [1 Y " 



HO 



130 



110 100 



90 m 



>A 



70 60 50 40 



Fig. 54. (A.fter Engelmann.) 



spectrum. A second maximum, and a third, appear at 59 

 and at 50 — 52, in the orange and green-blue, respectively. 



In the accompanying graph (Fig. 54) the ordinate gives 

 the energy absorbed (E'), In Engelmann's table the figures 

 give the proportions transmitted (E). 



*The figure i-6o = i-6 x 10,000 Angstrom units. A = 16,000 x 

 io~^ cm. 



