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56 INTERNAL STRUCTURE. nally, and do not owe their inclination to a fubfe* quent change. Refpe&ing the formation of ftrata and beds, many opinions have been propofed. Werner’s explanation is fatisfa&ory. He remarks, thatJlra- ta and beds appear to be particular and individual depojitions from a flute of folution or fufpenfion in water. The ftratified ftrutfture, as inay well be fuppo- fed, occurs in many different rocks, and, in a more extended view, probably in all. Gneifs, Mica- flate, and Clay-flate are always ftratified ; Granite frequently ; Sienite fometimes ftratified, fometimes unftratified ; Porphyry is feldom ftratified ; Pri- mitive-Limeftone occurs both ftratified and unftra tified: Flaetz-Limeftone, Sandftone, and Chalk, are moft diftindtly ftratified. When we examine the ftrudture of a mountain, we muft be careful that our obfervations be not too micrological, otherwife we ftiall undoubtedly fail in acquiring a diftinil conception of it. This will appear evident when we refledt that the geognoftic features of Nature are almoft all on the great fcale. In no cafe is this rule to be more ftriftly followed than in the examination of the ftratified ftrudture. By not attending to this mode of examination, geognofts have fallen into numberlefs errors, and have frequently given to extenfive tracts of coun try a moft irregular and confufed ftrudture. Spe culators
