Reason for which the Conditions of the Problem have been neglected.

The reason of this strange procedure will be discovered, when we reflect, that all geologists have hitherto been, either mere cabinet naturalists, who had themselves paid little attention to the structure of mountains, or mere mineralogists, who had not studied in sufficient detail the innumerable varieties of animals, and the infinite complication of their various parts. The former of these have only constructed systems: the latter have furnished excellent observations, and have laid the foundation of true geological science; but have been unable to complete the edifice.