A Fluorescent Colouring Matter. H. Wager. 159 



and that the green colour is therefore probably due to a com- 

 bination of these. The yellow j^ignient is soluble in water; 

 the blue pigment is soluble in alcohol in the presence of a 

 small quantity of water. The two colours can be separated by 

 capillary analysis on a strip of filter paper, by suspending the 

 strip of paper with one end dipping into the alcoholic solution. 

 As diffusion takes place the paper becomes coloured yellow 

 below, and blue-green above. 



The green alcoholic solution if allowed to remain in contact 

 with the Fungus soon becomes yellow, but still retains for some 

 time its green fluorescence. The blue pigment apparently 

 becomes changed, in the presence of the Fungus, to a yellow one. 

 This may be due to the action of an oxidase. A similar change 

 takes i^lace in the air dried Fungus. This retains its green colour 

 for some time, but gradually becomes brown. When the dry, 

 brown Fungus is soaked in water a dark yellow solution with 

 a green fluorescence is obtained. Water extracts nearly all 

 the colour, and if, after standing for some time in water, the 

 solution is poured off, and alcohol added, the alcohol remains 

 colourless. 



The green alcoholic solution is much more strongl}/ fluorescent 

 than the yellow watery solution, and if the green alcoholic 

 solution is decanted from the Fungus it retains its green colour 

 and strong fluorescence for a long time. After the lapse of 

 some months the solution becomes yellower, but the strong 

 fluorescence is maintained, and after two years is practically 

 as strong as at the beginning. The addition of a little sodium 

 hydrate, ammonium hydrate or hydrochloric acid to the green 

 solution changes it at once to ^^ellow, but the green fluorescence 

 persists. Hydrogen peroxide brings about a slow change in 

 the colour of the green solution to yellowish green but the 

 fluorescence remains. 



On evaporating the green alcoholic solution to dryness a 

 yellow amorphous pigment is left which gives when taken up 

 with water or dilute alcohol a yellow fluorescent solution, but 

 in absolute alcohol or ether gives only a faint yellow non- 

 fluorescent solution. 



Fluorescent pigments are widely distributed among the 

 Fungi, and they are also formed in many bacteria. Dr. A. 

 Weiss states that the majority of Fungi give a more or less 

 fluorescent pigment in alcohol*, but T find that in many species 

 no fluorescence is visible, and in many others is only very 

 slight. Thus the coloured species of Hygrophorus (yellow, 

 green, red) all give a bright orange coloured solution in alcohol 

 with a very slight green fluorescence. The bright green 



* S. B. K. Akad. Wiss. Wien, 1885. 



6—2 



