General Science. , ' ©7 
nion that this apartment was of great extent, and the strongest 
light we could obtain did not enable us to discern the roof. 
The light of the fire, strongly contrasted with, and gradually 
lost in the surrounding darkness, produced a very picturesque 
effect, which was greatly heightened by the situation of our par- 
ty, some of whom were obscurely seen standing upon the huge 
fragments of rocks, while others were passing and repassing in 
various directions, exploring a passage to the recesses of the 
cavern. Having groped about for some time, over and among 
rocks of all sizes and shapes, which were piled on each other 
in every possible manner, we at length discovered on our right 
a chasm about two feet in width. Looking into it from above, 
the space below appeared to enlarge, and the lava on which we 
stood to form the roof of another cavern beneath us. 
The floor was covered with fragments of every size, and from 
the roof hung stalactites of lava ; an appearance highly interest- 
ing, and which amply repaid me for the danger and difficulty en- 
countered. On breaking the stalactites, they were found to be 
much more porous and vesicular than any lava I had previously 
seen. The cells were nearly perfect spheres, arranged in con- 
centric circles, and most of them were large enough to contain 
a pea. They were not visible, however, till the stalactites were 
broken, being covered with a smooth and hard crust. The par- 
titions between the cells were less than the sixteenth of an inch 
in thickness, and had an imperfect glimmering lustre on the 
fresh fracture. Most of them contained a loose brown earthy 
matter, probably the result of partial decomposition. The sta- 
lactites externally, have a dark iron grey colour, sometimes 
passing to black ; and they are deeply enamelled in a longitudi- 
nal direction. They occur of all sizes ; some of them are less 
than an inch in length, while others exceed a foot. Their dia- 
meter is not less variable, but never exceeds six inches at the 
thickest part. Those which were about a foot in length were 
usually from one to three inches thick. 
The difficulty of penetrating to the last apartment of the ca- 
vern was by no means inconsiderable ; and for the last few yards 
we were obliged to creep upon the bottom, and advance with the 
utmost caution ; while the sharp points of hundreds of stalactites 
were in contact with one another. Some of the circumstances 
VOL. VIII. NO. 16. AFllIL 1823. J)d 
