Description of a Lake of Sulphuric Acid. 183 
& greenish-white, and charged with a quantity of the acid 
which escapes from the sulphur in combustion, occupies 
the lowest part on the south-west: from the surface a 
slight smoke rises. In the other part, which is about 25 or 
30 feet high above the lake, are the smoking vents. 
The sides of the volcano present nothing but white rocks 
cut into the form of needles; or rough, calcined, and re- 
duced by the effect of fire to the state of lime: in gome 
places they are covered with a greenish efflorescence. 
Towards the west and north-weést, the edge of the yol- 
cano is abrupt: its upper part is formed of thin layers of 
ashes or puzzolano, successively reddish, brown, white and 
yellowish : towards the east and south-east it inclines ima 
slope tolerably rapid to the half of its depth. Towards the 
south-west there is a section not very broad: it is by this 
aperture that the waters of the lake are discharged, which 
afterwards form the sulphuric river. At the summit of 
the crater, in the south-east part, we find ochrey, red and 
yellow earths. The slope which I have mentioned, si- 
tuated towards the east and south-east, is furrowed by the 
rain waters covered with volcanic tufa, sulphur, and yarious 
Kinds of lava in pieces of middling thickness. 
The trees adjoining the crater are small-sized, and a great 
number of them are withered. Nevertheless in the inside 
of the gulf, and even notwithstanding the sulphuric ex- 
halations, vegetation is not entirely extinguished: from the 
cleft in the rocks there issues a kind of fern, small and 
coriaceous, and a shrub of the arbutus kind, called, by the 
Javanese Roukom*: but what surprised me much was to 
find the excrements of tigers at the very edges of the cra- 
ter; for in this place the air is extremely cool in conse- 
quence of its elevation. 4 
Such are the observations which I made on the summit 
of the crater, We were very much fatigued, and we 
stopped some time to take rest and nourishment. During 
this time, the Javanese who accompanied us prepared and 
fastened the bamboo steps by means of which we were to 
descend to the bottom of the volcano. 
‘The place by which we descend is at the NNE: a part 
of the road is sloping: afterwards we are obliged to make 
use of ladders, which are attached to the rocks, sometimes 
perpendicular, sometimes inclined, according to the ground. 
This plan is dangerous : I should have preferred descending 
* I found the same plant when I made an excursion two years ago to 
examine another volcano situated at the summit of the Mar-api, or burning 
_ mountain, in the vicinity of Sourakarta, : 
M4 by 
