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stances, viz. basalt, wacke, porphyry-slate,and trap-tuff, are certainly not peculiar tothis formation, as in England, Scotland ,and Ireland , they are, often, found inter-stratified with other formations mucholder. There is reason to suspect that, inGermany , trap-rocks, of very different seras,have been referred to the same aera,and that much of that which has been sup-posed the newest fldtz-ti'ap in Scotland ,and which ought, therefore, to be moremodern than the beds of the basin of Paris ,is coeval with red sandstone, mountain-lime-stone, and coal.