Real and supposed effects of igneous action. 347 
tal strata vary from a few inches to hundreds of feet in thick- 
ness ; next above one of these strata is seen a space from 
one to ten feet wide, or high, that appears to have been in a 
state of fusion long after the mass above and below had be- 
come consolidated, in which forms it may be seen alternate- 
ly for hundreds of feet high, shewing caverns and fissures of 
all forms and sizes; some not unlike a common oven exter- 
nally, but much more spacious within, many of which were 
formerly used as repositories for the dead, especially when 
they were difficult of access. The volcano, of which I have 
made frequent mention, was measured by a surveyor of lord 
Byron’s, and estimated to be nine hundred and thirty-two 
feet down to the black ledge, and four hundred more down 
to the bottom; in all, thirteen hundred and thirty-two feet, 
so that you may form some judgment of the dimensions of 
the crater; the depth of a place that we supposed, on our 
first visit there, to be four hundred feet, is found, by meas- 
urement, to be nine hundred and thirty-two. Many times 
have I wished that you could accompany me to that won- 
derful scene.” 
Remarks on the specimens transmitted by Mr. Goodrich. 
They contain most of the usual volcanic products, and are 
remarkably interesting. 
1. Sulphur, of all the shades between white and yellow ; 
lelicat i tioned as being in the cocoa- 
the more ; g 
nut shells, are pieces of sulphur. In the collection are nu- 
merous crystals of sulphur, more remarkable for delicacy and 
richness of color, and finish of form, than for size. 
phur is found also investing or penetrating the proper lava. 
2. Siliceous sinter, white, porous, light, tasteless, harsh to 
the touch, readily scratches glass—resembles that of Ireland 
and the Azores. Mr. Goodrich remarks, that the white spe- 
cimens are from the bottom of the crater ; if he means these, 
as he probably does, may we not presume that the silex, dis- 
solved in water, probably containing alkali, and heated in- 
tensely under great pressure, was liberated when the wa- 
ter was rapidly evaporated, and thus the silex was deposited 
in a spongy form, as the steam and gases made their way 
through it. 
