Contributions to the Chemistry of Chlorophyll. 311 



and burns away, leaving no ash. When heated in a test-tube or 

 between watch-glasses, it gives a small quantity of amorphous brown 

 sublimate with a few crystalline needles. It dissolves in boiling alco- 

 hol, giving a bright yellowish-red solution, which, on cooling, deposits 

 crystalline needles, becoming almost colourless. It is moderately soluble 

 in ether, benzol, and glacial acetic acid ; very soluble in chloroform. 

 The chloroformic solution shows no absorption bands, only obscuration 

 in the blue. It is quite insoluble in caustic potash liquor even on 

 boiling. It dissolves in concentrated sulphuric acid, giving a dull red 

 solution, which, after the addition of a considerable quantity of acid, 

 shows no absorption bands, only obscuration in the blue and green ; 

 on the addition of water, the solution turns reddish-yellow without 

 giving any precipitate, but on standing for a short time the colour 

 turns to a fine violet, and then shows a broad ill-defined absorption 

 liand between the red and green. Not showing any very character- 

 istic reaction but the one last mentioned, it must remain doubtful how 

 and where it originates. It may possibly be a constituent of the 

 green parts of plants not hitherto observed, though I believe it myself 

 to be a derivative of chlorophyll meaning by chlorophyll the ensemble 

 of the colouring matters of green leaves formed by some unknown 

 process in the animal economy, but the fact of its solutions showing 

 no absorption bands does not lend countenance to this view. Having 

 also observed it on one occasion only, I do not feel justified in giving 

 it a name or in placing it in any known category of vegetable or 

 animal colouring matters. 



Another constituent of the faeces remains to be mentioned. It was 

 referred to above as showing in solution the absorption spectrum of 

 phylloxanthin. After all the substances capable of assuming a crys- 

 talline form have been separated from the alcoholic extract of the 

 faeces, this phylloxanthin-like substance is found in the final mother 

 liquor. I have not succeeded in obtaining it in a crystalline or any 

 other definite form, on account probably of the large quantity of fatty 

 matter with which it is associated ; but there is no reason, I think, to 

 suppose that it differs essentially from the phylloxanthin described in 

 previous communications as a product of the action of acids on chloro- 

 phyll. 



The conclusions to which the experiments above described lead may 

 be summarised as follows : 



1. The faeces of animals supplied with green vegetable food only 

 such at least as have so far been examined contain no chlorophyll, 

 but in its place substances which must be supposed to be derivatives 

 of chlorophyll, formed partly by the action of acids on the chlorophyll 

 of the food, partly by some agency to which the latter is subjected in 

 its passage through the body. 



2. Of these substances, one seems to be identical with phylloxanthin. 



