352 Scientific Intelligence. 
by a porous medium, the product of the slow digs end distillation 
going on escapes into the atmosphere, and is lost. ere the shales are 
gas elaborated are retained in the rocks, filling cavities by driving the 
water out by elastic pressure, aoe hamshensing porous strata embraced in the 
formation, or intervening between it and the impervious cover above. 
region of Canada and Michigan, fe sandstone is manta ut 
destruction of the outeropping sha ological agencies has wats 
an immense deposit of pa Tab pig ‘ari material, which forms an Im- 
rvious shy for the petroleum be killen the lower portion 
upon the surface of the rock, is dark thi k, and impure, 
but a moderate price ~ cules of distillation, It is now oe wal 
festations is of a dark color. Black 1i river of SMhiges seems to be the 
counterpart of Black creek of Enniskillen. It would seem evident that 
the color of the water in both cases must ue to some constituent of 
the crude oil; and yet a chemical examination of the water of | 
river taken at Port Huron, did not sustain my expectations. It should be 
tested six or eight miles further nort 
hen we compare the more direct indications, rig ee is 
equally complete. The oil region of Michigan aboun “ gum beds,” 
or masses of inspissated oil, some of which have hago to the char- 
acter of asphalt. The oil is still issuing, and it shows itself on the sur- 
face of standing water everywhere throughout the Baker tract. More- 
to e wi th noise and violence gt the bottom we wells. In ee in- 
stance the jet, when lighted, illuminated the country over a radius of four 
mi iles, and the sound was like that of steam escaping from a high-pressure 
engine. Many similar cases have occurred. 
