ly smelliug fumes, wliich condensée! to a colourless uily liquid, 

 which on standing in the air hecame bnnvn and on being heated with 

 hvdrochloric acid gave a red powder. We ocmeluded tliat the 

 substance produced was ])yrriiline and that chlDniphvll niav be ]ios- 

 sibly a i)yiTuline derivative. Last ycar Nencki and I -1 ubtained froni 

 phyllocyanin cupric acétate bv treating it witli livdroiodic acid and 

 pbosphonium iodide a base whicli under the influence of air gave 

 urobilin. The properties of tlie base nientioned reniinded me forci- 

 bly of tlie substance we had obtaiiied with Dr. Schunck liv ineans 

 of the reaction described above and I thought it interesting en- 

 ougli to ascertain in what rehxtionship the twu substances, the one 

 obtained by dry réduction tlie other by bydroiodic acid stand to eacli 

 other. I found. that the two substances were identical. Tliis is proved bv 

 the foilowing e.xperiments. 1 gr. phyllocyanin, obtained by E. Schuncks 

 method was mixed with 10 gr. of zinc tlust and the mixture heated 

 in a glass tube. Very soon there may be noticed in the cold parts 

 of the tube oily drops of a liquid, which turns rapidly reddish 

 brown. After cooling the tube was extracted with warm alcohol. fil- 

 tered, to the filtrate water added and Kltered again. A sample of 

 the filtrate gave with mercuric chloride a white precipitate. The 

 remaining liquid was lei't to stand in the air; after some 

 time a red colouration was noticeable and on doser examination 

 a verv fine red precipitate observed. By adding alcohol to this 

 mixture and boiling up a reddish brown solution was obtained. 

 whieh on being exaniined through the spectroscop showed an absorp- 

 tion band in front of the F line. Theaddition <]f asolution of zinc chloride 

 in alcoholic ammonia caused a green fluorescence and the liquid on 

 being again examined spectroscopically showed also a band in 

 front of F. These tests show, that the red colouring matter obtained 

 from phvllocyanin in the manner described above is identical with 

 urobilin and that the volatile substance, obtained bv heating phyl- 

 locyanin with zinc dust, cannot be anything eise but haeniopyrrol. 



III. 

 The absor|)ti(in spectra of phylloixtrpli) riii salts in aequoiis solutions. 



It is weil known. that one of the inferences of the theory of 

 electrolytic dissociation is. that in the case of quantitativelv disso- 



=) 1. «. 



