PLA 



572 



PLE 



name of piaster after it has become dry 

 and hard. In pharmacy, a compound, gene- 

 rally oxide of lead and olive oil, for apply 

 ing externally. 



PLAS'TER OP PAH is. A preparation of a 

 sub-species of gypsum, cn\\e A plaster- stone, 

 dug near Montmartre, in the neighbour- 

 hood of Paris. AVhen the stone is cal- 

 cined, and the powder made into a paste 

 with water, it quickly sets, and has its 

 hulk increased at the same instant, so 

 that, under the name of stucco, it has 

 been much valued for modelling and like 

 purposes. 



PLAS'TK: CL\T. In geology, a name for 

 one of the beds of the eocene period, from 

 its being used in the manufacture of pot- 

 tery, frXeurTHif , n't for the art of fashion- 

 ing. The plastic clay is a marine deposit 

 answering to the London clay of English 

 geologists. 



PLAS'TRON (French). 1. A sort of lea- 

 thern pad used by fencers to defend the 



body against thrusts. 2. A name for 



the sternum of reptiles. 



PLAT'AKVS. The plane-tree. A genus 

 of trees. Monoe-cia Polyandria. Name 

 from srAari-f, broad, in allusion to the 

 size of the leaves. The two principal 

 species are the oriental and occidental, the 

 one a native of the Levant, and the other 

 one of the largest trees of North Ame- 

 rica. 2. The tree which bears the 



name of plane in England belongs to the 

 genus Acer. See PLANE. 



I- LATE. The denomination usually 

 given to gold and silver wrought into 

 articles of household furniture. Gold 

 plate pays a duty of 17s., and silver plate 

 a duty of 1*. 6d. per oz. "Watch-cases, 

 chains, collars, &c., are exempt. 



PLAT'BAND. In architecture, any square 

 moulding with little projection, as the 

 fasciae of an architrave, the list between 

 flutings, &c. The platband of a -window 

 or door is the lintel when it is made 

 square and not much arched. 



PLAT'FOND, ) (French). Tie ceiling of 



PLA'FOND, . a room, the bottom of the 

 projection of the Cannier of the cornice ; 

 a soffit. 



PLAT'FORM A row of beams -which 

 support the.jnmber-work of a roof lying 

 at the top of a wall ; also any erection of 

 a temporary kind having a floor of boards, 

 stone, &c., for some immediate purpose. 

 The term is properly applicable to any 

 elevated floor not wholly surrounded, as 

 the floor of a stage, hustings, scaffold. &c. 

 2. In ships, the orlop (q. v.). 



PLAT'INA. The Spanish word for pla- 

 tinum (q. v.), from plata, silver, or the 

 river Plata, near which it was first found. 



PLA'TIKQ, OR PLATED MANUFACTURE. 

 The art of covering other metals with 

 11 vex so as to give the articles manufac- 



tured somewhat the appearance of silver 

 plate. 



PLAT'ISUM, Sp. platina. A metal which 

 is found in flat grains, of a grayish- white 

 colour, like tarnished steel, and contain- 

 ing always some other metal, as palla- 

 dium, rhodium, osmium and indium, in 

 alloy. The metal when pure resembles 

 polished steel, is harder than silver, about 

 double its density, ductile, malleable, 

 and unalterable in air or water, and has 

 not its polish impaired by a wiite heat. 

 Like gold it is only soluble in nitro hy- 

 drochloric acid ; but, unlike gold it can- 

 not be fused in any considerable portion 

 by the strongest heat of our furnaces, but 

 may be welded like iron at a white neat. 

 It is found in South America, the Ural 

 mountains, and in minute quantity in. 

 Spain and Bavaria. It is about half the 

 value of gold. 



PLATON'IC YEAR. The great year. The 

 period of time determined by the revolu- 

 tion of the equinoxes, upon a supposition 

 of the precession going on uniformly till 

 they have made a complete revolution. 



PLA'TOON. 1. A small square body of 

 soldiers, drawn out of a battalion of foot, 

 whan they form a hollow square, to 

 strengthen the angles. 2. A small body 

 acting- together, but parate from the 

 main body. 



PLATS (of a ship): Fli -opes of rope- 

 yarn woven together and used for the 

 same purposes as marline. 



PI-AT'TING. In commerce, slips of bast, 

 cane, straw, &c., platted or plaited tot 

 making hats, <&c. 



I*LATYDAC'TYLI, pi. ofplatyaactylus,from. 



A suivgenus of nocturnal lizards, Gecko- 

 tida, from the Mauritius. See GECKO. 



PLAT'YPUS. The name given by Shaw 

 to the Ornithorhynchu* of Blumenbach, 

 from w^aKri/;, broad, and from, a foot. See 

 ORNITHOKHTNCHCS. i 



PLEA, Norm. pie. 1. In late, that which 

 is alleged by a party in support of his 

 demand ; but, in a more limited and tech- 

 nical sense, the answer of the defendant 

 to the plaintiff's declaration. Pleas to the 

 action are an answer to the merits of the 

 complaint, which confesses or denies it. 

 - 2. A cause in court. 



PLEADINGS. In law, the mutual alter- 

 cations between a plaintiff and defendant, 

 or written statement of the parties in 

 support of their claims, comprehending 

 the declaration, count of narration of the 

 plaintiff, the plea of the defendant in 

 reply, the replication of the plaintiff to 

 the defendant's plea, the defendant's re- 

 joinder, the plaintiff's sur-rejoinder, the 

 defendant's rebutter, &c., &c., till the 

 question is brought to issue, that is, t 

 rest on a single point. 



