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of vegetable matters, of which it is so evidently composed. Thedistinctness of vegetable form and structure, which is thus displayed,and which incontestably proves their previous existence in this mass,serves also to refute the opinion, promulgated by Pliny , and adoptedby Schoockius and others, of this substance being entirely of mineralorigin; and of its being originally formed in its present situations.

Those who have endeavoured to account for the formation ofpeat, by the sinking of large floating islands, which have afterwardsbecome covered by the accumulation of strata of other earth, ap-pear, certainly, to have mistaken the cause for the effect. This will1 think appear sufficiently plain by examining the following verycurious account of the appearance of these islands, as well as ofthe phenomena which precede and accompany their formation, asgiven by a gentleman who appears to have almost witnessed theseparation of these floating islands in the lake of Derwentwater.

The lake of Derwentwater is celebrated for the astonishing phe-nomena its waters exhibit. At uncertain times the waters of thislake experience very considerable agitations, the waves running toa great height, and forming large white breakers, on which theboats are tossed as though in a severe storm; whilst none of theusual causes of such commotions of water are discoverable. Thewaves differ from those produced by ordinary causes; not rolling■ along from one end of the lake to the other; but rising, in moun-tainous heaps, from ten inches to two feet in height; as thoughtraised by some powerful elevating force, applied underneath: and,in agreement with the idea thus suggested, the people of the neigh-bourhood term this phenomenon a bottom wind. Sometimes thewhole surface of the lake is thus agitated, at other times it is onlypartially affected; and frequently it will strike a boat with so muchforce, that it will appear as though it had struck against a rock : avery considerable roaring noise often accompanying these surprisingappearances.