The Probert Encyclopaedia of General Information

BOG

Bog is the name given to a piece of wet, soft, and spongy ground, where the soil is composed mainly of decaying and decayed vegetable matter. Such ground is valueless for agriculture until reclaimed, but often yields abundance of peat for fuel.

A bog seems usually to be formed as follows: A shallow pool induces the formation of aquatic plants, which gradually creep in from the borders to the deeper centre. Mud accumulates round their roots and stalks, and a semi-fluid mass is formed, well suited for the growth of moss, particularly Sphagnum, which now begins to luxuriate, continually absorbing water, and shooting out new plants above as the old decay beneath; these are consequently rotted, and compressed into a solid substance, gradually replacing the water by a mass of vegetable matter. A layer of clay, frequently found over gravel, assists the formation of bog by its power of retaining moisture. When the subsoil is very retentive, and the quantity of water becomes excessive, the superincumbent peat sometimes bursts forth and floats over adjacent lands.

Bogs are generally divided into two classes: red bogs, or peat-mosses, and black bogs, or mountain mosses. The former class are found in extensive plains frequently running through several counties, such as the Chatmoss in Lancashire, and the Bog of Alien in Ireland, the depth varying from 3.6 to 13 metres. Their texture is light and full of filaments, and is formed by the slow decay of mosses and plants of different kinds. The lower parts, being more entirely decayed, approach nearer to the nature of the humus than the upper portion, and, as being more carbonaceous, are more valuable for fuel. Black bog is formed by a more rapid decomposition of plants. It is heavier and more homogeneous in quality, but is usually found in limited and detached portions, and at high elevations where its reclamation is difficult.

In Ireland bogs frequently rest on a calcareous subsoil, which is of great value in reclaiming them. In the reclamation of bog land a permanent system of drainage must be established; the loose and spongy soil must be mixed with a sufficient quantity of mineral matter to give firmness to its texture and fertilize its superabundant humus; proper manures must be provided to facilitate the extraction of nutriment from the new soil, and a rotation of crops adopted suitable for bringing it into permanent condition. The materials best adapted for reclaiming peat are calcareous earths, limestone gravel, shell-marl, and shell-sand. Thoroughly reclaimed bogs are not liable to revert to their former condition. Trunks of trees are often found in bogs as are also bones of extinct animals.
Research Bog