in the glass-trade, a term used for a sort of potash made use of in many of the glass-works, particularly for the green glass. It is the calcined ashes of a plant called by the same name; and in some places, of sea-thongs or laces, a sort of thick-leaved fucus or sea-wrack. This plant is thrown on the rocks and shores in great abundance, and in the summer months is raked together and dried as hay in the sun and wind, and afterwards burnt to the ashes called kelp. The process of making it is thus: The rocks, which are dry at low water, are the beds of great quantities of sea-weed; which is cut, carried to the beach, and dried: a hollow is dug in the ground three or four feet wide; round its margin are laid a row of stones, on which the sea-weed is placed, and set on fire within, and quantities of this fuel being continually heaped upon the circle, there is in the centre a perpetual flame, from which a liquid like melted metal drops into the hollow beneath: when it is full, as it commonly is ere the close of day, all heterogeneous matter being removed, the kelp is wrought with iron rakes, and brought to an uniform consistence in a state of fusion. When cool, it consolidates into a heavy dark-coloured alkaline substance, which undergoes in the glass-houses a second vitrification, and attains a perfect transparency; the progress by which thus a parcel of sea-weed, formerly the slimy bed of seas or dreary shelter of shell-fish, is converted into a crystal lustre for an assembly-room, or a set of glasses for his majesty's table, is a metamorphosis that might be a subject for an entertaining tale.