No. 200.J ' 
46 
bor, near the shore of the lake, there is supposed to be a sufficient sup- 
ply of it to light a city. It is employed in the light-house at the har- 
bor seventy-five feet above the level of the lake. 
To these localities, I may also add another which I visited in com- 
pany with Drs. Walworth and White, and Mr. Storkc, situated in the 
valley of the west branch of the Canadawa creek, four miles southeast 
of Fredonia. Here is a spring in a marsh which has a whitish color, 
caused by the bubbles of gas which rise through the clay forming the 
bed of the spring. The water is fresh and pure, and has a temperature 
of about 50° F. The gas, when collected and forced through a small 
orifice, burns with a blueish white flame. 
General views. — The evolution of this gas is so abundant, and ex- 
tends over such a large surface, that we must refer its origin to some 
general cause. The strata of slate, as I have already remarked, have 
thin seams or patches of a bituminous matter, which burns with a flame 
entirely resembling that of the gas which is so copiously disengaged 
through its fissures. With this slate, there alternates a sandstone, 
which every where contains small cavities filled with petroleum; and 
all the specimens of which give out a strong bituminous odour. This 
liquid substance appears to have originally been diffused throughout the 
whole mass of the rock, both sandstone and slate, and to have given to 
it the peculiar character which it now possesses. 
It is probable that the gas so copiously discharged, is formed by the 
action of heat upon the bituminous matter thus generally diffused 
through the strata of sandstone and slate; or it may be that the same 
matter which, in the upper strata is solid or liquid, is, at greater depths, 
the gas kept in a liquid form by the pressure of the superincumbent 
strata. A fact which I observed at Fredonia, confirms this view, and 
in my opinion proves that there is at some distance below the surface, a 
vast reservoir of gas, the evolution of which is prevented by the pres- 
sure exerted upon it. The fact to which I refer is, that when the wa- 
ter in the creek is low, bubbles of gas are often observed, which disap- 
pear entirely when the water has risen, as after a rain. And again, 
gas may be obtained at almost any part of the bank by boring to the 
depth of twenty or thirty feet. So common, indeed, is this occurrence, 
that many of the wells in the village of Fredonia are strongly charged 
with the gas. It may also be added, that there are frequently to be 
observed in this vicinity disruptions in the strata of slate, which have 
probably been caused by some expansive force exerted from beneath. 
