370 Scientijic Intelligence—Geology. 
hydrogen, and carbon equally ancient ? Is there any rock so old that 
it does not contain sulphur, The dolomites of the metamorphic 
rocks contain carbon; and the carbonates generally carry about one- 
eighth of their mass of this singular substance, which is sometimes 
an imperceptible vapour, and acquire the hardest kind of matter 
known, ‘These dolomites are sometimes found older than the Pots- 
dam sandstone. Nitrogen may not have been found in rocks below 
the mountain limestone, where it exists in the form of the nitrate of 
potassa. But nitrogen must have been in being before organic life ; 
for it is one of the component parts, and there could not have been 
an atmosphere fit for respiration without it. 
Hydrogen is not found in combination with the strata of the 
early geological eras; but hydrogen must have been present, with 
oxygen, before water could have been formed; and consequently, be- 
fore the deposition of any sedimentary rock. If the ancient seas 
which deposited the Silurian system, were, as their fossils prove them 
to have been, salt, then their water contained chlorides and chlorine 
in the same manner as our seas do at the present day. 
All the gaseous substances exist now in a free state in the oldest 
sedimentary strata, and flow out in combination with salts in thou- 
sands of mineral springs. The thermal springs that proceed from 
great depths in the lowest and oldest rocks, bring up carbonated hy- 
drogen and other gases, and chlorides, carbonates, &c., in solution. 
Almost all the salt wells and the petroleum springs in the above list 
evolve gases, some of them pure nitrogen, and salts of various kinds. 
All those kindred substances are found wherever man has penetrated 
the earth or divined its composition, in the oldest as well as in the 
most recent formations, and they include all the constituents of 
bitumen. 
Chemists regard the various forms of native bitumen, whether 
under the name of naphtha, petroleum, seneca oil, mineral tar, or as- 
phaltum, as essentially the same compound mixed with different pro- 
portions of earthy matter, or exposed more less to the atmosphere, 
which coagulates and hardens it. It is an atomic combination of 
carbon and hydrogen—6 atoms of each. In the atmosphere it ab- 
sorbs oxygen and nitrogen. From the same rocks and the same 
depths there issues in company with naphtha, petroleum, &c., an in- 
flammable or light carburetted hydrogen gas, composed of 1 atom 
of carbon to 2 of hydrogen. 
Having convincing proofs that the elementary substances compris- 
ing bitumen were in existence and universally diffused in nature be- 
fore the production of organic life, with the same chemical affinities 
they now possess and obey, is it philosophical to suppose that they 
did not, when in contact, obey those affinities until after animals and 
vegetables were created? Is it not equivalent to the assertion that 
carbon and hydrogen did not unite in the proportion of 6 atoms of 
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