Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/380

358] PEA the different liquors have subsided, the fluid pint is carefully decanted ; when a pearly matter, of an oily consistence, remains at the bottom 3 which is denominated by the French, Essence d'orient. A small portion of this matter is dropped in a hol- low, blueish glass-bead^ that is gently agitated, till the whole in- ternal surface is completely lined ; when the cavity is tilled up ^ith wax, in order to impart solidity and weight. Peails thus nianufa£lured, possess fewer blemishes than such as are natural or genuine, to which they are fully equal, in point of brilliancy. PEARL-ASH, a kind of fixed alkaline salt, prepared in various parts of Europe, and also in Ame- rica, by melting and extrading the salts from the ashes of burnt vege- tables ; and, after evaporating the moisture, and reducing them to dry- ness, by calcining such ashes for a considerable time in a furnace m.o- dcrately heated. — See Alkalies. The best pearl-askcs are obtain- ed from weeds, the ashes of which yield a larger, proportion of salt than most kinds of wood. And it appears from the numerous experi- irsents of Mr.KiKv.'AN, that, among weeds, the fumitory produces the greatest quantity of salt ; and next to it, WORMWOOD 3 though he ob- serves, that if we attend only to the proportion of salt in a given weight of asles, those of worm- v.ood contain the most. — The Tre- foil-BucKBEAN (Menijanlhes tiijh- liata, L.) also produces a larger ^quantity of ashes, and salt, than fern. Pure pearl-ashes .should possess a very acrid, caustic taste, and be uniformly white; though such cri- terion is not always to be relied Wiii^i as they ^re iVecuently aduL- PEA terated with lime and salt ; im- positions, not easily discovered by the eye. In order to deleft this fraud, let a small portion of the suspefted pearl-ash be exposed to the air till it become soft, when it should be held over the fire in a shovel : if the alkali contain any common salt, the latter will crackle, and a slight explosion will take place, as soon as it becomes hot. Pearl-ashes are very generally employed in the manufadure of glass ; for they combine with earths in a proper degree of heat, and form a vitreous mass : they are also used for domestic purposes, in washing linen, &c. : and are sub- jeft to a duty of 2s. 5ld. pet cwt. ou importation : but, by the 24 Geo. II. c. 51, § 2, 3, both pearl, and pot-ashes, may be imported duty-free from the British colonies of America. In 17pl, a patent was granted to Mr. George Glenny, for his method of obtaining a larger pro- portion of pearl and pot-Oi/ws fiom those of wo(jd, than that which is usually procured. — The patentee's process consists in calcining the common wood-ashes in a furnace ; previously to which, a small quan- tity of lime is to be sifted among them, to prevent the mass from vi- tret'ying} though, if the latter be continually stirred during the pro- cess of Ci'.lcination, the addition of limewill be unnecessary. Vv'henthe ashes are calcined into a fine pow- der, they may be treated in the usual manner ; but he observes, that it will be better to boil them in large vessels, especially during frosty weather. PEAllLWOllT, the Procum- bent, Trailing Pearlwort, or Break-stone, Sagi/ia procum- Icns, L. ail indigenous perennial Plantj