388 BACTERIOLOGICAL CHEMISTRY 



II. Insoluble in chloroform — 



(a) Soluble in water, e.g. the anthocyanins 



of some species of Fusarium. 



(b) Insoluble in water — 



(1) Soluble in alcohol, e.g. violacein 



from Chr. violacemn ; violet 

 and purple pigments of similar 

 species . 



(2) Insoluble in alcohol — 



(a) Soluble in alkali, e.g. the 

 yellow pigments of some 

 Micrococci ; aspergillin 

 from the spores of A. 

 niger. 



{{i) Insoluble in alkali, e.g. the 

 black pigment of B. 

 mesentericus niger. 



B. Extra-cellular Pigments colouring the medium. 

 I. Soluble in water — 



(a) Soluble in chloroform, e.g. pyocyanin, 



the blue pigment of Ps. ceruginosa. 

 (h) Insoluble in chloroform — 

 ^ (1) Colour change with acid and 



alkali, e.g. the green fluores- 

 cent pigment of Ps. cerugiiiosa 

 (colourless in acid), red pig- 

 ment of Sacch. pulcherrimiis 

 (colourless in alkali) ; 

 methoxydihydroxytoluquinone 

 from P. spiniilosum (blue in 

 alkali, purple when neutral, 

 yellow in acid). 

 (2) No colour change with acid or 

 alkali, e.g. the red pigment of 

 some species of Actinomyces. 



