BLUE PIGMENT IN COKAL AND OTHER ANIMAL ORGANISMS. 261 



amyl alcohol, but on boiling it yields a dull greenish coloured 

 solution. It is also insoluble in amyl acetate. It is insoluble in 

 ether, ethyl acetate, and chloroform; also in acetic anhydride 

 although glacial acetic acid is one of its best solvents. 



When boiled with dichloracetic acid it yields a pale green 

 solution, with monobromacetic acid it yields a pale grass-green 

 solution changing to a greenish-brown on boiling. 



It is insoluble in oil of winter-green (methyl salicylate). 



It is but slightly soluble in aldehyde, in paraldehyde and in 

 acetone. It is insoluble in glycol; with glycerol it gives a pale 

 greenish solution which quickly fades; it also imparts a pale green 

 colour to hot dichlorhydrin. 



2. Hydrocarbons. — It is not dissolved by kerosene, naphtha, 

 nor by the pure paraffins, neither is it soluble in such olefines as 

 caprylene and octylene, the latter however acquires a slight green 

 tint when heated with the pigment. 



With eucalyptus oil it yields a pale green solution and leaves a 

 greyish gelatinous-looking residue of proteid matter, many times 

 the volume of the original pigment, with black specks of the 

 colouring matter embedded in it. 



It does not yield a coloured solution with turpentine, either 

 hot or cold, but after standing in it for some weeks the turpentine 

 lost its original pale straw coloured tint and became viscid, the 

 pigment also lost its colour and left a grey residue or skeleton. 



3. Acids. — With nitric acid the pigment gives a yellow or 

 orange coloured solution fading to yellow, probably due to the 

 formation of picric acid. The colour is not restored by alkalis. 



It has already been stated that the pigment is insoluble in 

 hydrochloric acid. 



It is insoluble in dilute sulphuric acid, 1 to 4 aq., but with 

 concentrated sulphuric acid it gives a greenish coloured solution 

 in the cold ; on boiling the colour darkens, and on filtering through 

 glass wool an almost black liquid is obtained; on dilution a dusky 



