PL A t^e height of four feet from the root J the stragglins^ side-branches of the other part of the hedge mast also be lopped, and several of the remaining shrubs separated closely from their roots ; after which, the rest are transversely cut half way through, so that they may be bent to one side. These are next intlecled in a position nearly horizontal, and interwoven with the upright stakes, in order to retain them in that si- tuation. Farther, where hedges have been deformed with gaps, the divided quicksets ought to be laid very low at those particular spots, which should be supported by tiie addition of some dead stakes, or truncheons of willows. These wattlings will continue to vegetate, sending forth shoots from their stems ; and, as the upright branches that arise from the stakes (the tops of which had been cut off) in a short time force themselves up- wards through the hedge, they ,wjll unite the whole into an entire body, so as to constitute a strong, durable, and elegant fence. The operation of plas/iing is sometimes performed in Odober, but more generally in the month of February or March ■. which lat- ter seasoil is the more eligible, be- cause tiie divided plants wiil not be materially injured by the vernal frosts. PLASTER, an external applica- tion of a more solid consistence than ointments, and which is usual- - ly spread on linen, leather, or tow, according to tiie nature of the wound or ulcer. Plasters arc prepared chiefly from unctuous matters, which are com- bined with powders, so as to retain their firmness when cold, without adhering to ,the tinkers ; though becoming soft and pliable in a low PL A [399 degree of heat, and acquiring suf- ticicnt tenacity from the warmtli ot thi^ human body, to adhere l& the part to which they are applied. Tii(=! consistence of these com- pounds varies, according to the dif- ferent parts of the body, for which they are intended. Thus, if ther be designed for the stomach or breast, it will be necessary to make them very soft and pliant : one ounce of expressed oil, with a si- milar quantity of yellow wax, and halt an ounce of any suitable povV- der, will form a convenient plaster. But, if the preparation be required for the limbs, it ought to be made more lirm and adhesive : hence, a double portion of wax, and an ad- ditionallialfounce of powder, should be properly incorporated, and spread on leather, linen, or tow, in the usual manner, London coicrt-plaster : Dissolve the best isinglass (previously cut in small pieces) in any proof spirits, so as to obtain a strong viscid solu- tion ; then take taffety, or other thin silk, and spread theliquor uni- formly over it, with a soft brush : when the lirst coat is perfectly dry, repeat tiiis application a second and third lime, liil at length the whole surface shDuld be sparingly anoint- ed with Peruvian balsam. — Others prepare this noted plaster, by dis- solving equal parts of storax in the cane ; benzoin, the resin ; and isinglass, in spirits of wine : these ingredients are to be digested in a glass retort, placed in a moderate heat for twenty-four hours ; when the solution is liltered, and applied while lukewarm, in a manner simi- lar to the preceding, but without any balsam. — See also Wart and Wound, PLASTER OF PARIS, a pre- paration of several species of gyp- sum.
