Geological Survey of the State of New York. 107 
time of the Romans, the rock salt was only discovered in 1828, 
and the section given of the saliferous marls at Stoke Prior, 
(from the pamphlet of Dr. Hastings,) shows not only an associa- 
tion of salt and gypsum as usual, but, what is of peculiar inter- 
est to our subject, the “red and green marl traversed by veins of 
gypsum, usually vertical, one hundred and ninety-five feet,” and 
succeeded (series descending) by ‘red marl, containing ‘rock 
salt,’ nearly pure, distributed like the gypsum in the overlying 
mass,” twenty-four feet, and by five layers of rock salt, and four 
others of “red marl with veins of salt,” and all in the space of 
four hundred and sixty feet. If these marls have firmness enough 
to cohere, were the salt dissolved out by the surface waters perco- 
lating through the strata, they would present very similar phenom- 
ena to those exhibited by our porous rocks, which, however, have 
probably a firmer structure, and though some of the gypsum, by 
the same causes, would be removed, yet the quantities of each 
dissolved would be in a ratio probably not far from that of their 
solubility, or as one to two hundred, while the proportions found 
in solution in the brine springs, that have escaped decomposition, 
according to the analysis of several Onondaga springs, are about 
as one to thirty or thirty-five. In the saliferous group of Monroe 
and Ontario, “small particles and seams of gypsum still remain, 
scattered through the marl, in which there are the usual depos- 
its of masses of this mineral. Owing to the usually soft nature 
of these rocks, they have been removed, as described in Ononda- 
ga, from extensive tracts, and the space has been filled with allu- 
vium from more northern rocks, throughout Seneca, Ontario, 
Wayne, and Monroe counties, and the red shale therefore does 
not appear between Cayuga Lake and Genesee River, though in 
some places, the red color of the soil indicates its proximity. The 
theory of the formation of the salt and gypsum, and the indications 
of igneous agency suggested by the geologists, may more appropri- 
ately be referred to when we have their mature views. It would 
seem, however, that, with the coal formation of Pennsylvania at 
one extreme of the series, and the primary rocks of New York at 
the other, and the intervention of four thousand feet of strata be- 
tween the saliferous group and the coal, and the discovery of the 
true old red sandstone in the series above the rocks of New York, 
and the coincidence of the organic remains of the New York 
rocks with those of the Silurian system, the proper geological re- 
