THE PETROLEUM SPRINGS OF WESTERN CANADA. 317 
on his lands are a sure indication that here the petroleum existed in the 
greatest abundance, and nearest to the surface. 
The material penetrated is a very stiff light-colored clay—in some 
cases almost pure white—no doubt chiefly derived from the ruins of 
decomposed rocks similar to those underlying the clay; unequivocal 
evidence of which is found in the fact that the clay contains numerous 
fossils identical with those embedded in the rocks, which are found at 
various depths, alternating with beds of clay, and consist of thin strata, 
more or less of a shaley nature, plentifully charged with the fossils 
peculiar to what is called the Hamilton group of the Devonian system 
of rocks. No rock of a bituminous nature seems as yet to have been 
struck ; although detached masses of bituminous shale, identical with 
that which crops out at Kettle Point, on Lake Huron, and containing 
about fourteen per cent. of volatile matter, are frequently met with in 
forming the wells. * 
The depths hitherto penetrated vary from 40 to 120 feet; and in 
this respect little advantage seems to be obtained by commencing 
operations on the low grounds, as along the flats of the creeks; for at 
Mr. Williams’ wells the depth is only about 40 feet, while at others in 
the immediate vicinity, on the flats of Black Creek, where the ground 
is at least 40 feet lower, although the depth penetrated is three times 
as great, the supply obtained is as yet inconsiderable. The strength 
of the oil, also, as indicated by the hydrometer, varies to a considera- 
ble extent in different wells, even although they may be very near 
together ; and the supply to each well, at least in the southern part of 
the township, seems to be independent ; these facts indicating the deep- 
seated origin of the oils. Here also the oil seems to be diffused 
throughout the clay, penetrating through numerous vertical cracks or 
fissures both in the rocks and clay, evidently in obedience to some 
force from beneath; no doubt due to the pressure of gas, which 
invariably issues in great quantities with the oil, giving to the wells 
the appearance of boiling caldrons of pitch. These gases produce a 
remarkable effect on the men who work in the wells, greatly resembling 
that caused by the inhalation of nitrous oxide or laughing gas ; and, 
in order to the continuance of their operations, it is necessary to clear 
away the gas from time to time by exploding it. It has recently been 
ascertained that the vapours of naphtha, anilene, and other hydro- 
carbons produce physiological effects, resembling those of chloroform 
and other anzesthetic agents. 
