1895.] Contributions to the Chemistry of Chlorophyll. 317 



barium salt leading for the acid to the formula CgoH^Og, and it is, he 

 states, a very unstable body. The absorption spectrum of its solu- 

 tions shows six bands in the relative positions indicated by him, 

 Among the products of decomposition of dichromatic acid mention is 

 made of a substance which in acid solutions shows only two bands ; 

 this substance Hoppe-Seyler calls phylloporphyrin. Another product 

 of decomposition is obtained, according to him, on evaporating the 

 ethereal solution. Sachsse obtained by fusion of his /3-phEeochloro- 

 phyll with soda a reddish-brown product dissolving in acids with a 

 violet colour, and having the formula C 2 6H3 3 N 3 2 . Similar experi. 

 ments made with phyllocyanin, which led to the formation of a 

 purple crystallised substance, have already been described in the 

 fourth memoir of this series. The product formed in all these cases 

 being doubtless the same, we shall adopt for it the name phyllopor- 

 phyrin, Hoppe-Seyler's body of the same name being, in our opinion, 

 simply a compound with acid, not a product of decomposition. The 

 substance has, in fact, a pronounced basic character, and shows in 

 neutral solutions a spectrum differing entirely from that of its acid 

 solutions. 



Preparation and Properties of Phylloporphyrin. 



The method of preparing the substance from phyllocyanin has 

 previously been described. The method before given is, however, 

 not an advantageous one, the yield being trifling, and the quantity of 

 bye-products formed at the same time relatively large. We there- 

 fore adopted another process, avoiding the use of melted alkali in 

 open vessels and employing alcoholic potash in sealed tubes. The 

 material employed was phyllotaonin, which, being itself a product of 

 decomposition of phyllocyanin with alkali at lower temperatures, 

 and being more easily prepared in a state of purity than phyllocyanin, 

 seemed better adapted than the latter for the preparation of phyllo- 

 porphyrin. The process employed was as follows : Ethyl phyllo- 

 taonin in crystals was treated with alcoholic potash in sealed tubes 

 at 190 for several hours. On opening the tubes no pressure was 

 observed. The brownish-red contents were poured out, mixed with 

 water and an excess of hydrochloric acid, and then shaken up with 

 ether. The ether acquired a fine purple colour, and left on evapora- 

 tion a brownish residue in which dark purple crystals were discern- 

 ible. The residue was treated with boiling alcohol, which dissolved . 

 part, leaving a quantity of brown matter undissolved. On adding to 

 the filtrate an alcoholic solution of zinc acetate, and allowing it to 

 stand, a red crystalline deposit a zinc compound of phylloporphyrin 

 was formed. This was collected and dissolved in boiling alcohol. 

 The solution, after addition of a little hydrochloric acid, was mixed 



2 A 2 



