410 Scientific Intelligence, 
pal one is cos a noise resembling that made by an immense cauldron 
of boiling w 
The crs. shane of the vapors varies much in the different interstices. 
In the crater of the southeast, the vapors of the highest interstices a 
nearly 188°-6 Fahr., whilst in the lower ones the temperature was only 
140° Fahr. In the principal crater, the hottest vapors did not come up 
to 194° Fahr.; in the largest interstice that I have observed, into which 
a person could easily enter, if the thick column of vapor r would permit 
him, the temperature was only 98°6° Fahr. at three feet of depth. Filling 
a graduated tube with water, and placing it within the interstices, I col- 
the gases several times in order to analyze them, and, moreover, 
rver. 
‘The solid eats ts of the — are the sublimed sulphur which 
covers almost all the stones sen ures; anda whi te salt which ae 
Known by the name of “ alumbre ps se or Solate alum. 
in water, it crystallizes by spontaneous evaporation in a derivative form 
of the oblique rhomboidal prism. Besides these —* there is found 
scoria, composed of melted sulphur and ashes of pyroxene and aon rite, 
more or less calcined or altered by the — * the watery va 
The cpiatie miele I collected in the era which you a had the 
to . 
a hia re vi tem ate ture—87° abe): Polypodi ‘um erenulatum, 
saersing to the crater in the present year, in eden to pass some days 
Within it; I consider my late expedition only as a preparatory 
_ Recessary step towards another more important one. Before undertaking 
it, I will ascertain the point from whence the descent to the bottom 
Pevneti i is likely to be easiest, avoiding the imminent peril 
x oneself wh descending th rn wall. In 1 
e rp 1844, M. 
unately saved himself in time from rolling headlong into 4 
- A similar accident befell me in 1845; and in 
son, who ac i | me, nearly found his grave in the 
ee eigeaot dacs 
