PEAT. The natural accumulation of vegetable matter on the surface of lands not in a state of cultivation ; always more or less saturated with water, and generally abounding in modifications of extractive matter, varying with the nature of the plants of which the peat is composed. Peat is generally of a black or dark brown color, or, when recently formed, of a yellowish brown : it is soft, and of a viscid consistence ; but it becomes hard and darker by exposure to the air. It is generally more or less mixed with earthy substances. When steeped in water it gives out a brown liquor, more or less dark. When thoroughly dried it may be set fire to and burns slowly, giving out a gentle heat without much smoke. This smoke communicates a peculiar fla vor to all the articles with which it comes in contact ; and this flavor is considered a characteristic of spirits which have been distilled in vessels heated by this kind of fuel, and also of malt, corn, and fish which have been dried by it. Peat abounds in every part of the world, but more espe cially in the cold moist climates of tem perate regions, and generally in those parts of Europe where the ground is moist without natural drainage, and where the sun's light is obscured by clouds. It covers many thousand acres in Ireland, and in the Highlands and western counties of the Lowlands of Scot land, and in the western counties of En gland; but all these bogs are rapidly dis appearing, in consequence of being drained, and having their surfaces slight ly covered with earth, and stirred and sown with grass seeds.
When peaty matter accumulates on the sides of acclivities it is generally compar atively dry, and is then called hill-peat; but when peat accumulates on hollow places, or on flat surfaces, it is generally thoroughly saturated with water, and is then called peat-bog. In most cases the principal plant which forms the peatty matter is the Sphagnum paluetre of Lin ineus ; a moss which is common on all moist peaty surfaces throughout Europe, and is frequent in many parts of North America. This moss continues growing
upwards from the points of the shoots, while decay is advancing in a similar manner from their lower extremities ; thus forming a thick, close mass of vege table matter, which rots below as it in creases in height. The rotten part is fre quently dug out and dried, to be used as fuel, or to be mixed with dung or lime and rotted into manure.
When peaty matter accumulates on a surface which abounds in springs, the water sometimes oozes out beneath the peat, and between it and the natural soil, in such quantities as to raise up the layer of peat, and float it off to a distance ; sometimes carrying every thing before it, and ending by burying under it lands in a state of culture. About the middle of the 18th century, a remarkable irruption of this kind took place near Annan in Dumfries-shire ; and such irruptions are frequent in Ireland. The circumstances favorable to the growth of peat are a soil abounding in springs, a flat surface or hollow surrounded by hills, and a moist climate. Hence peat-bogs are more abun dant in Ireland, and in the western coun ties of Scotland, than in any other part of the British empire.
When an accumulation of peat has taken place in a level situation, or on an acclivity not abounding in springs, the matter accumulated is comparatively dry, and is then called peat moss. One of the most remarkable peat mosses in Brit ain is the Flanders Moss, in Stirlingshire. It rests on a flat surface of excellent allu vial soil, of which it covers about 4000 acres. Great part of this peat moss, 1,eing quite light, has been cut into small pieces, and floated off, by means of a stream of water, to the sea ; thus expos ing the natural soil, and rendering it fit for culture. This operation was com menced at Blair-Drummond, towards the end of the last century, by the celebrated Lord Kaimes, and is still continued by his son, Mr. Drummond.