No. 200.J 
71 
Similar deposits and petrifactions are very frequent in the county of 
Onondaga. At the ba^^e of a hill near Syracuse large masses of tufa are 
to be seen. More extensive deposits occur in the towns of Marcellus 
and Camillus; and here, trunks of trees and aggregates of leaves and 
roots converted into pure carbonate of lime are not uncommon. 
Calcareous tufa is also found in great abundance near the Genesee 
falls at Rochester, in Cayuga county; near Ithaca in Tompkins; also 
near the falls of Niagara, and in various other places which it is scarcely 
necessary to particularize. At the Niagara and Genesee falls, large 
masses of moss are found incrusted with carbonate of lime, evidently 
caused by the carbonate of lime held in solution by the waters which 
are continually passing over them. These incrustations, therefore, are 
undoubtedly to be referred to causes now in operation. 
The vicinity of Chittenango probably affords the best opportunity for 
studying the circumstances attending the conversion of vegetable mat- 
ter into carbonate of lime. And for the purpose of arriving at some 
conclusions with regard to these, I subjected to analysis various portions 
of the tufa or petrified vegetable matter, together with some of the 
water which issued from a side-hill and appeared to be the agent con- 
cerned in the petrifying process. 
The petrified wood was found to consist almost entirely of carbonate 
of lime, with very minute and variable portions of silica, alumina, and 
oxide of iron. As I have before remarked, in some specimens not a 
trace of vegetable matter was discoverable, while in others its presence 
could be easily detected. It is evident, therefore, that while the struc- 
ture of the plant remains entire, the vegetable matter by the petrifying 
process is wholly or in a great measure, replaced by the carbonate of 
lime. 
From the side-hill at the base of which these specimens of petrified 
vegetables occur, springs of water every where burst out. The super- 
incumbent rock contains a large proportion of carbonate of lime, and 
the sulphate of lime is also found in beds enclosed within it. The com- 
position of this water is what might be expected from the nature of the 
strata through which it passes. The water from one of these springs 
had a faint smell of sulphuretted hydrogen, and contained a little car- 
bonic acid. In 1000 parts, I found 
Solid matter, consisting of carbonate and sulphate of 
lime, and sulphate of magnesia, . . , 1 . 94 
Water, 998.06 
1000.00 
