33^ CHEMICAL EXAMINATION OF A LIQUID 
taneously, yielded arenaceous crystals, of a yellowish-red 
tint : examined by the lens, these were found to be chiefly 
octahedral ; some seemed to be duodecahedral. Stars 
formed of groups of transparent and diaphanic acicular 
crystals also pervaded the liquid mass — (Muriate of pot- 
assa ?) 
This volcanic liquid is unusually interesting from its 
containing iro7i associated with nichel and titanium^ and 
particularly remarkable for holding in solution the consti- 
tuents of meteoric stones^ with the solitary exception of 
silica. This liquid must have been ejected in the form of 
vapour, and subsequently condensed. The fact clearly 
proves the susceptibihty of iron, thus combined with nic- 
kel, &c. being held suspended in the atmosphere. In refe- 
rence to silica, we have Dr Macculloch's authority for 
assuming that it may be sublimed ; and in the thermal 
waters of Lucca, Bath, &c. it is intimately combined with 
oxide of iron, where it seems to act the part of an acid. 
Before that I can believe aerolites to be the exotic growth 
of an extra atmospheric locality, I must possess more ample 
evidence than has yet been adduced. 
Among a variety of interesting minerals from the Lipari 
Islands which the Earl of Mountnorris presented to me, 
two merit particular notice ; and both of them, his Lord- 
ship told me, w^ere from the crater of Vulcano. One formed 
part of a stalactitic mass of Jhimy — and the other. Lord 
Mountnorris assured me^ had been pronounced to be 
Baryta. 
By reducing a portion of this volcanic alum to powder, 
and triturating it with a saturated solution of pure caustic 
potassa, ammoniacal gas was copiously evolved, and deci- 
ded by its odour, — white fumes, with muriatic acid, and 
violet tint, with cupreous solutions. The alum was some- 
what granular and spongy, and on its solution in distilled 
