No. 200. 1 
69 
Petrifying Springs. 
The history of petrifying springs affords a fine illustration of the inti- 
mate relations which exist between the researches of the chemist and the 
geologist. For whatever difference of opinion may prevail concerning 
the true theory of the petrifying process which in many situations is daily 
going on, there is no doubt of the general fact, that chemical agencies 
are largely concerned in it. 
The explanation ordinarily given of the formation of travertin or cal- 
careous tufa, stalactites, &c. is sufficiently simple, and may be easily 
comprehended. The water in certain springs holds in solution conside- 
rable quantities of carbonate and sulphate of lime, and occasionally of 
silica, which are deposited when the water comes into contact with the 
air. This process is well exemplified in the formation of those small 
stalactites which are often found attached to the arches of aqueducts on 
our canals. The water contained in these aqueducts percolates through 
the limestone of which they are constructed, and thus becomes charged 
with carbonate of lime, which it again deposits when exposed to the 
air.* Many localities occur in this State, where extensive calcareous 
incrustations are formed in a similar manner. There is a very interest- 
ing exhibition of this kind near Camillus, in Onondaga county, where, 
below the marly clay and beds of gypsum, these calcareous incrustations 
are found, which are both fibrous and crystallized — sometimes existing 
in regular strata, and at others forming the walls of cavities, of various 
figures and dimensions. 
Simple as the explanation of these phenomena may seem, when it is 
known that water in its natural state always contains air and carbonic 
acid, which enable it to hold in solution a small quantity of carbonate of 
lime, it is not so easy to comprehend all the circumstances w^hich attend 
the process of petrifaction, or the conversion of vegetable into stony 
matters; for it is to this only that our attention will at present be di- 
rected. That the most delicate parts of vegetables should be replaced 
by carbonate of lime, or silica, without any alteration of their form, is 
certainly one of the most curious operations going on in the laboratory 
of nature. I shall therefore offer no apology for presenting a brief no- 
tice of these springs, and a few suggestions concerning the mode in 
which they produce these singular results. 
As might be inferred from what has already been said, these petrify- 
. ing springs are most common in limestone regions. They therefore 
* The stalactites pendant on the arches of the aqueducts of our canals, have been called ni- 
trate of lime ; but all those which I have examined are pure carbonate of lime. 
