MOLLUSCA. 131 
by Signior Bezio as a peculiar substance which he has de- 
nominated Melaina. It is obtained by digesting the ink 
with very dilute nitric acid, until it become yellowish, wash- 
ing it well, and separating it by the filter ; it is then to be 
frequently boiled in water, one of the washings to be a lit- 
tle alkalized; and, finally, with distilled water. The me- 
laina is a tasteless, black powder, insoluble in alcohol, ether, 
and water, whilst cold, but soluble in hot water; the solu- 
tion is black. Caustic alkalis form with it a solution even 
in the cold, from which the mineral acids precipitate it un- 
changed. It contains much azote. It dissolves and de- 
composes sulphuric acid. It easily kindles in the flame of 
acandle. It has been found to succeed as a pigment in 
some respects, better than China ink. (Dub. Phil, Trans. 
Nov. 1825.) 
The Cephalopoda are all inhabitants of the sea. They 
are widely distributed, occurring in the arctic as well as the 
equatorial seas. In the latter, however, they grow to the 
largest size. It is reported, that in the Indian seas, boats 
have been sunk by these animals affixing to them their long 
arms, and that they are dreaded by divers. 
The two Linnean genera, Nautilus and Sepia, compre- 
hend all the animals which are at present considered as be- 
longing to this class. 
OrvDER I.—_ NAUTILACEA. 
Furnished with a multilocular shell. ) 
This order is involved in the greatest obscurity. None 
of the recent species have been subjected to an accurate 
examination, so that their connection with the order Sepia- 
cea may still be considered doubtful. Enough is known of 
