ASSIMILATION OF CARBON 



II 



The absorption spectra of chlorophyll a and chlorophyll b, in acetone, are 

 shown in Figs. 5 and 6, reproduced photographically, these being taken from 

 Willstatter and S toll's monograph (Tafel VIII). Five different concentrations 

 are employed, the strongest being represented by the lowest spectrum in each 

 case. The Fraunhofer lines and wave-lengths (in mm) are shown above/ 



The spectrum of living leaves shows the same absorption bands as does the 

 spectrum of an alcoholic solution of chlorophyll (ethyl chlorophyllide) ; in the 

 former case the bands are merely displaced a little toward the infra-red end of 

 the spectrum. 9 



The researches of Schunck and Marchlewski 1 have contributed much to an 

 understanding of the chemical character of chlorophyll. The action of hydro- 

 chloric acid upon an alcoholic chlorophyll solution produces first chlorophyllan, 

 then phylloxanthin, and finally phyllocyanin. The interesting substance phyl- 

 lo porphyrin 2 (C 16 H 1S N 2 0, or C32H36N4O0) 3 is obtained by treating phyllocyanin 

 with strong alkalies. Phylloporphyrin crystallizes in beautiful, dark red-violet 



p IG » — Absorption spectra of phylloporphyrin (i, 3, 5) and of hematoporphyrin (2, 4, 6); 

 1 and 2 in ether; 3 and 4 in hydrochloric acid; 5 and 6 in zinc chloride solution. (After Schunck 

 and Marchlewski.) 



crystals, is slightly soluble in alcohol and ether, and more readily soluble 

 in chloroform. The absorption spectrum of its ethereal solution (Fig. 7) 

 exhibits seven absorption bands, the first of which lies to the right of the red 

 region of the spectrum, between C and D, and is very distinct. 



Phylloporphyrin is of great interest because of its close relationship to 



1 Schunk, E., and Marchlewski, L., Zur Chemie des Chlorophylls. Liebig's Ann. Chem. u. Pharm. 



278: 329-345- 1894. 



* Schunck, E. and Marchlewski ; L., Zur Chemie des Chlorophylls. (Zweite Abhandlung.) Liebig's 

 Ann. Chem. u. Pharm. 284: 81-107. 1805. 



'Willstatter, Richard, and Fritzsche, Hermann, Ueber den Abbau von Chlorophyll durch Alkalien. 

 Liebig's Ann. Chem. u. Pharm. 371: 33-124- 1909. 



' These two figures are added by the editor. — Ed. 



It seems highly probable that the chlorophyll of living leaves exists in colloidal solution. 

 (Herlitzka, A., Neben den Zustand des Chlorophylls in der Pflanze und iiber kolloidales 

 Chlorophyll. Biochem. Zeitsch. 38: 321-330. 1912. Iwanowski, [D.], Ueber das Verhalten 

 des lebenden Chlorophylls zum Lichte. Ber. Deutsch. Bot. ges. 31: 600-612. 1913). — Ed. 



