Besides the great use of charcoal in the composition of gunpowder, and to artists and manufacturers of different kinds, it has lately been employed, with considerable success, in correcting the rancid and disagreeable smell of train oil, so as to render it fit to be burned in chamber lamps; and several manufactories of this oil have been established in the neighbourhood of London. Newly-made charcoal, if rolled up in clothes which have contracted a disagreeable odour, will effectually destroy it; and if boiled with meat beginning to putrefy will take away the taint. This substance is used by artists in the polishing of brass and copper-plates, for the drawing of outlines, and numerous other purposes. When purified, it forms perhaps the best tooth-powder that is known. The mode of purifying it is to reduce it to powder, wash it repeatedly with water, and then dry it by means of a strong heat in close vessels. This heat expels the foreign contents with which it is impregnated; but however intense, if the vessels are closed, it in no respects alters the quality of the charcoal. The vapour of burning charcoal is extremely pernicious; and persons exposed to it in confined rooms are liable to be suffocated in a very short time. The best remedy is immediately to take them into the strongest draught of cold air that can be obtained, to loosen all their garments, and apply volatile spirits to their nostrils. 238. _CORK is the external bark of a species of oak_ (Quercus suber) _which grows in Spain, Portugal, and other southern parts of Europe, and is distinguished by the fungous texture of its bark; and by its leaves being evergreen, oblong, somewhat oval, downy underneath, and waved._ The principal supply of the cork that is consumed in Europe, is obtained from Catalonia in Spain; and the culture and the preparation of it yield to the inhabitants of that province near 250,000_l._ per annum. In the collecting of cork, it is customary to slit it with a knife, at certain distances, in a perpendicular direction from the top of the trees to the bottom; and to make two incisions across, one near the top and the other near the bottom of the trunk. For the purpose of stripping off the bark, a curved knife with a handle at each end is used. Sometimes it is stripped in pieces the whole length, and sometimes in shorter pieces, cross cuts being made at certain intervals. In some instances the perpendicular and transverse incisions are made, and the cork is left upon the trees until, by the growth of the new bark beneath, it becomes sufficiently loose to be removed by the hand.