1896.] Contributions to the Chemistry of Chlorophyll 235 



been variously described. On examining a concentrated solution of 

 haematoporph yrin in dilute hydrochloric acid, two very dark bands 

 are seen separated by an extremely narrow space, the one nearest the 

 blue end Laving one edge shaded off. On gradual dilution, the two 

 bands become narrower, and between tliem there then, appears a third 

 band which, with a narrow slit, remains visible even on great dilu- 

 tion. The same phenomena are seen in the case of phylloporphyrin. 

 Lastly, the zinc salt of ba?matoporphyrin in solution shows two ab- 

 sorption bands, just as does that of phylloporphyrin. The facts just 

 described point, notwithstanding the differences observed, to some 

 near relationship between the two bodies. They suggest the possi- 

 bility of our being able to convert one into the other, or at least of 

 obtaining by appropriate treatment some derivative common to both, 

 such as the product described by Neneki and Sieber, due to the action 

 of nitric acid on haamatoporphyrin. The difficulty found in obtaining 

 sufficiently large quantities of the two substances in a state of purity 

 constitutes a formidable obstacle to the success of any such attempts. 



We beg, in conclusion, to thank Professor Neneki for a specimen 

 of heematoporphyrin hydrochloride which he kindly presented to us. 



C I> 3E F G 



EXPLANATION OF FIG-UKE. 

 • Absorption Spectra of Phylloporphyrin, Hsematoporphyrin, and several of their 



compounds. 

 1. . Phylloporphyrin in ether. 



2. Hsematoporpliyrin in ether. 



3. Phylloporphyrin in hydrochloric acid. 



4. Haematoporphyrin in hydrochloric acid. 



5. Phjlloporphyrin-zinc, in alcohol. 



6. Hsematoporphyrin-zinc in alcohol. 



B 2 



