150 



David L. Drabkin 



150 



250 



30 



Multiples of 40 = 4 5 6 7 



9 10 II 



600 500 



tT\/i 



Fig. 5. Comparison of absorption spectra of K3Fe(CN)6, haematoporphyrin (in 

 alkaline solution), cyanmethaemoglobin or ferrihaemoglobin monocyanide (from 

 dog haemoglobin), and ferriprotohaemin dicyanide or haemin dicyanide at pH 13. 

 Hogness and colleagues (1937) reported a maximum at 230 m/t (corresponding 

 with V X 10~^ = 435), with e = 32-1, for haemin dicyanide. The abscissal scales 

 indicate the postulated locations of bands in the equally spaced, frequency 

 distributed series (Drabkin, 1936, 1938). 



■xlO" 



Multiples of 40=4 



\ 



n\// 



Fig. 6. Comparison of spectra of cyanmethaemoglobin (from the haemoglobin 

 of man), ferricytochrome c cyanide at pH 10 to 11 (for preparation see legend 

 to Fig. 7), and cyanmetmyoglobin (from horse heart myoglobin). The remarkable 

 similarity of these spectra is evident. The abscissal scales indicate the postulated 

 locations of bands in the equally spaced, frequency distributed series. 



