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CHAPTER XIX. 
Proofs of Design in the Dispositions of Strata 
of the Carboniferous Order. 
In reviewing the History and geological position 
of vegetables which have passed into the state of 
mineral coal, we have seen that our grand supplies 
of fossil fuel are derived almost exclusively from 
strata of the Transition series. Examples ol 
Coal in any of the Secondary strata are few and 
insignificant; whilst the Lignites of the Tertiary 
formations, although they occasionally present 
small deposits of compact and useful fuel, exert 
no important influence on the economical con- 
dition of mankind.* 
Before we bad acquired by experiment some extensive 
knowledge of the contents of each series of formations which the 
Geologist can readily identify, there was no a priori reason to 
exjject the presence of coal in any one Series of strata rather 
than another. Indiscriminate experiments in search of coal, in 
strata of every formation, were therefore desirable and proper, 
in an age when even the name of Geology was unknown; but 
the continuance of such Experiments in districts which are now 
ascertained to be composed of the non-carboniferous strata of 
the Secondary and Tertiary Series, can no longer be justified, 
since the accumulated experience of many years has proved, 
that it is only in those strata of the Transition Series which have 
been designated as the Carboniferous Order, that productive 
Coal mines on a large scale have ever been discovered. 
