137 
affected or inkindled at the same time, as those I have mentioned to have 
been the causes of the islands far distant from the continents. 
“ Nor do I conceive that all those clusters were all thrown up at once, as 
the Grecian islands in the Archipelago , the Fast-Indian Islands in that part 
called the South Sea , the Maldivia near the coast of Malabar, the islands 
scattered at the North of Madagascar, the islands to the south-west of St. 
Helena in the Atlantic ocean, Finidada dos picos, the isles of Cape Herd, 
Canaries, Orcades, Src. also the Gallopegas and others in the Pacific Sea, or 
Mar del Zur ; but rather that some were made in one age, and some in other 
ages of the world. And this was timed as the several magazines came to be 
ripened and then fired; they only indicating, as I conceive, that in those 
places of the terrestrial globe, there were placed the proper mineral ferments 
or seeds as it were of them, which, when the convenient times were come 
and accomplished, then they were put into act, and then they produced their 
effects, which are the islands that now remain the lasting monuments of them. 
Nor can I suppose that all the magazines of the earth of this kind are blown 
up and spent, but that there may be many other yet remaining for the future 
ages to be made sensible of their effects.” Such were the conjectures of Hook. 
Since the discovery of the composition of water, and our present know¬ 
ledge that carbonaceous substances decompose this element, setting free 
its inflammable air, and that most caverns are replete with this gas*, we 
* In many of the chambers of coal-mines, notwithstanding the shafts, the inflammable air is so 
predominant that the colliers are obliged to work by the light of a machine, constructed of flints and 
iron, which a boy keeps turning, for this gas is not inflamed by the spark, like gunpowder, whereas 
it kindles in an instant from flame, and has often thus produced the most terrible destruction, before 
this invention of light from flint and steel was made by a steward of the late Earl of Lonsdale. The 
inflammable gas mixed with a certain proportion of atmospheric air may be breathed with impunity. 
That undaunted aerinaut Pilatre de Rozier, before a large company at Paris, inhaled it pure, and emit¬ 
ting it from his nostrils and mouth in the dark, set fire to the air in its passage, and realized the fabu¬ 
lous account of Cerberus, who is represented as vomiting out fire. Once attempting to mix it with 
one-ninth part of atmospheric air, and then setting it on fire, so terrible an explosion was produced, 
that he imagined all his teeth had been driven out. As to mixed hydrogenous air we have the authority 
of, Spallanzani. 
“ On this plain it was, that, formerly, stood the furnaces on which the sulphur of Yulcano was puri¬ 
fied. But this useful labour had been long since abandoned, and even prohibited, from the supposition 
that the vapours arising from the purgation of the sulphur were prejudicial to the plantations of vines 
in Lipari. A few years ago, indeed, it was again resumed, by the special permission of his Sicilian 
Majesty; but was soon again given up, not because any fear was then entertained that the vines would 
be injured, which the more judicious of the natives of Lipari are now convinced is a vulgar error, since 
they sustain no damage from the smoke of the crater of Yulcano itself, though that is beyond all com¬ 
parison more in quantity than that produced by the purification of the sulphur: nor was it abandoned 
because the quantity of sulphur obtained was. too little to repay the trouble and expence, as the vein. 
2M 
