Description of a Lake of Sulphuric Acid. 185 
for in this place the subterraneous bellowing is much more 
considerable, and one of them every ten seconds throws to 
the distance of eight or ten feet pieces of melted sub- 
stances as large as a man’s fist. When these dejections 
take place, they occasion a hissing like that of the air 
which escapes from a fire-engine; the intervals between 
‘the dejections are very regular. ‘These substancss in the 
dark appear as if inflamed; but in the day-time they have 
the appearance of lumps of mud, which flatten in the act 
of falling. I was very desirous of procuring a specimen of 
these substances as soon as thrown out; but, both on ac- 
count of their situation and the heat of the ground, it ts 
impossible to approach nearer than 15 feet. All this part. 
of the bottom of the volcano also presents other small aper- 
tures; the smoke issues from all the fissures of the crust 
upon which we tread; and even upon making an opening 
with a spade, the smoke immediately escapes. The nature 
of this place indicates that it is subject to daily revolutions; 
masses of rocks more or less calcined, masses of ashes 
more or less hardened, are heaped up without regularity, 
and present the image of disorder. The ground on which 
we tread is formed of a succession of layers of white puz- 
zolano containing globules of black glass in the form of 
tears. We meet with abundance of pieces of lava and of 
black glass of different forms and sizes, and sulphur of 
‘different degrees of purity. We also find alum and vitriol 
formed in some stones. 
The Javanese say that the vents two years ago were to 
the westward of those which now exist; we still see traces 
of them there: they are extinguished, and form pits of 25 
or 30 feet in depth. Formerly, also, a person might have 
reached the edge of the lake of sulphuric acid without dif- 
ficulty; but at present all the banks are rugged: it is at- 
tainable, and that with great difficulty, at one side only, 
where a Javanese drew up, by means of a bamboo, a speci- 
men of the water at my desire. The place from which 
sulphur was extracted two years ago is covered with water. 
Our excursion was near being attended by a tragical 
event. M. Lisnet, having approached too close to the edge 
of the lake, threw down a portion of the crumbled ashes 
upon-which he stood; he was carried down some way ; and 
but for a rock which luckily arrested his progress, he would 
have perished by a miserable death in the lake. 
We remained about an hour and a quarter at the bottom 
of the volcano. I have drawn an interior view of it 
(Plate 11.) which will show better than my-description the 
disposition 
