MELAIN. 127 



light. When in powder, it has a fine velvet black colour, has no 

 smell, it taste is saltish, and its specific gravity about 1-640. 



Dr Prout analyzed a portion of this dry matter, and found its 

 constituents as follows : 



Melain, . 78-00 



Carbonate of lime, 10-40 



Carbonate of magnesia, 7-00 



Common salt? \ 2 .ig 



Sulphate of soda, / 

 Mucus, . . 0-84 



98-40 



Melain has a fine full black colour, and possesses the shining 

 appearance of powdered charcoal. It is insoluble in muriatic 

 and sulphuric acids, even when assisted by heat ; and also in 

 acetic acid. Concentrated nitric acid acts on it readily, and with 

 considerable energy, abundance of red fumes being emitted, 

 and at length a partial solution being formed of a very deep 

 reddish-brown colour. Potash added to this solution occasions 

 no precipitate ; but carbonate of potash occasions a slight 

 one. Caustic potash ley, when assisted by heat, effects a partial 

 solution of melain. So does caustic ammonia, but in a slighter 

 degree. The colour of these alkaline solutions is a darker brown 

 than of the solutions in nitric acid. When muriatic or sulphu- 

 ric acid is dropt into the alkaline solution, a slight precipitate 

 falls ; but this does not happen when nitric acid is employed. 



Melain burns without melting and with considerable difficulty, 

 emitting the usual smell of burning animal matters, somewhat 

 modified by a fishy odour. When burnt, it left a minute portion 

 of reddish ashes, consisting of a mixture of peroxide of iron, lime, 

 and magnesia. 



Melain is insoluble in water, but mixes with that liquid readily 

 and remains long suspended ; but the addition of the mineral 

 acids or ammonia causes it to subside rapidly. It is insoluble in 

 alcohol and ether. 



Melain may be obtained from the dried ink of the cuttle-fish 

 by boiling that substance in water till every thing soluble in that 

 liquid is taken up. It is then treated in the same way succes- 

 sively by alcohol and muriatic acid. Thus purified, it is to be 

 well-washed with water, containing towards the end a little car- 

 bonate of ammonia. 



