the lixivious-ashes of certain vegetables, used in the making of glass, soap, &c.

The method of making pot-ash is directed by Dr Shaw, as follows. Burn a quantity of billet-wood to grey ashes; and taking several pounds of these ashes, boil them in water, so as to make a very strong lixivium, or lye. Let this lye be strained through a coarse linen cloth, to keep out any black parts of the half-burnt wood, that might happen to remain in the ashes: then evaporate this strained lye in an iron-pan over a quick fire almost to dryness; then taking out the matter remaining at the bottom, and putting it into an iron-crucible, set it in a strong fire till the matter is melted, and then immediately pour it out upon an iron-plate, where it soon cools, and appears in the form of a solid lump of pot-ash. Much after this manner is pot-ash made in the large way of business, for the service of the soap-boiler, glaze-maker, fuller, &c., but according to the difference of the wood or combustible matter employed, with the manner of turning it, and conducting the process, different kinds of pot-ash are prepared.