SIO j)r Webster's Account of the HoUSprmgs of Furnas 
specimens of which, I found the heat and acid fumes almost 
suffocating. Every stone has been more or less changed, while 
not a shrub or plant flourishes for many yards around. The 
thermometer introduced into the fissures immediately rose to 
120®, and in some places to 123° Fahrenheit. 
Sulphur is so abundant and pure, that it might be collected 
in quantities sufficient to export ; wherever a loose stone lies 
over one of the fissures, or where many stones are loosely heap- 
ed together, their under surfaces are soon covered with it ; and 
by placing tiles, as is done at Solfatra, on which the sulphur 
could collect, an abundant supply of it would be obtained* 
Wherever the water has flowed, depositations of siliceous 
sinter have accumulated, and circular basins, composed entirely 
of this substance, have been here and there formed round a 
spring. The siliceous matter rises, in many places, eight or ten 
inches above the level of the water, and is often exceedingly 
beautiful. Grass, leaves, and similar substances which have 
been exposed to the influence of the water, are more or less 
incrusted with silex, and exhibit all the progressive steps of pe- 
trifaction ; some being soft, and differing but little from their 
natural state ; while others are partly converted into stone, or 
are entirely consolidated. In many instances, alumina is the 
mineralizing material, which is likewise deposited from the hot- 
waters. I found branches of the ferns which now flourish on 
the island, completely petrified, preserving the same appearance 
as when vegetating, excepting the colour, which is now ash-grey. 
Fragments of wood occur, more or less changed, and one en- 
tire bed, from three to five feet in depth, is composed of the 
reeds so common on the island, completely mineralized, the 
centre of each joint being filled with delicate crystals of sulphur, 
in elongated, double four- sided pjn’amidical crystals, with a 
highly resinous lustre. 
Round the springs, where the water has dashed irregularly 
over the edge of the basins, the depositations of siliceous mat- 
ter are rough, and often present an appearance similar to those 
of Iceland, which have been so well compared, by Sir George 
Mackenzie, to the heads of cauliflowers The variety of sili- 
* In the year 1817, I had an opportunity of examining the interesting suite 
of Icelandic specimens dej^oaited by Sir George Mackenzie, in the apartments of 
