120 An ANALYSIS of 
and I may offer what I have imagined, without its being thought 
neceflary to make an apology. Profeffor Berncman confidered 
the filiceous earth in thefe waters as diffolved by the power of | 
the hot water alone; and fuppofed, that water, aided by excef- 
five heat, became a folvent of this fpecies of earth. He formed 
this opinion, however, under difadvantageous circumftances, 
and from a partial view of the fubjeét. He only knew that 
this earth is actually diffolved in thefe waters, and depofited by 
them, and that they fpring out of the ground of a full boiling 
heat, with appearances of their having been hotter below. 
He did not know what other ingredients they contained along 
with the earth, As we now know they contain an alkali, 
which is a powerful medium for combining this earth with 
water, I do not think that the power of water alone to diffolve 
it can be admitted, until it is proved by direct experiments ; 
and I am not of opinion that thefe will fucceed. I am perfuaded 
that both the filiceous and the argillaceous earth have been dif- 
folved by the medium of the alkali, but at the fame time that 
the violent and long continued heat contributed greatly, and 
was even neceflary to this diflolution. The proportion of the 
cauftic alkali to the earthy matter in one of thefe waters, is as 
134 to 100; in the other it is 16 to roo. When we form arti- 
ficial compounds of filiceous earth and alkali in thefe proportions, 
we find that cold water has no power to diflolve them, though 
boiling water, by length of time, would certainly act on them. 
Even cold water, or the humidity of the earth, is well known 
to penetrate the hardeft glafs that is expofed to it for years or 
for ages; and [ have had the experience of the power of hot 
water to act on glafs, when I have diftilled water in the fame 
glafs retorts a great number of times, or evaporated water often 
in other glafs-veflels. heir internal furface was evidently 
affected by the continued ation of the hot water. Its firft ef 
feét is to foften thin laminz at the furface of the glafs, and to 
make them feparate from that furface, in confequence probably 
a of 
