Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/192

 PAR

PAR

Such were, however, the opinions of authors about this tab- ifance. Of late we have been taught to think it loft; but it is ftill common on the fhores of moll: of the iflands of the Archipelago, tho' not obferved or regarded ; and is truly a very heavy and tough clay of a fine white colour, found in maffes of different fizes, generally as foft as the fofter clays within the ftrata ; and by rolling about on the beech in this ftate, it gathers up the fand, fmall (hells, and other foulnefTes we al- ways find about it. It is moft probable, that there are ftrata of it fine and pure in the cliffs there, and that the fea wafhes off maffes of them in ftorrns and high tides, which are what we find. Hill's Hift. of Foil", p. 17.

PARGET, in natural hiftory, a name given to the feveral kinds of gypfum or platfter-ftone, which when (lightly calcined, make what is called plai/ier of Paris, ufed in cafting ftatues, in ftuccoing floors and cielings,'and many other like occa- fions.

The word parget, tho' generally underftood of all the gyp- fums, is, however, by the workmen principally applied to the two fpecies which make up the flrft genus of that clafs, called by Dr. Hill the pholides. Thefe are the Montmartre kind, and that of Derbyfhire. See Pholis. The firft of thefe, or parget of Montmartre, is dug in the place from whence it has its name, and is very pure; of a confiderably bright and gloffy appearance : when frefh broken, of a clofe, firm, and compact texture, and fomewhat foft and fmooth to the touch. It is found in maffes of different fizes, from four inches to as many feet in diameter; and of no determinate fhape or figure, but ufually fomewhat flatted. It is ufually of a pure and fine white, tho' fometimes a little brown ifli; and in both cafes fo exactly refembles in ftru£ture and appearance, a lump either of coarfer or finer loaf fugar, as not to be eafily diftinguifhed from it at fight. When broken, it looks confiderably bright, and is feen to be com- pofed of fmall flat particles laid together with no order or re- gularity. It will not give fire with fteel, nor ferment with aqua fortis ; but very freely calcines to a fine white powder, the ufes of which are well 'known. We have none of this kind in England. Hill's Hift. of Foff p. 112. The Derbyfhire parget of this genus, (for there are many of the others dug in the fame county, which are much lefs va- luable) the pholis of that country, as it ought diftinclly to be called, which is what our workmen diftinguifh by the name of Derby/hire parget, of all the gypfums comes the neareft the nature of the French. This is diftinguifhed from all the other Englifh gypfums by its fuperior hardnefs, its brightnefs, and the breadth of its conftituent particles. It is of an extremely irregular, rough, coarfe, and unequal tex- ture, and is not at all foft to the touch. It is very beautiful- ly variegated in colour with a fine bright white, and a dufky pale red. The white is ufually the ground, and the red is difpofed in form of clouds, fpots, or veins in it. It is found In broad flat maffes of uneven and rugged furfaces ; fome of thefe are four or five feet in breadth, and two or three in thicknefs.

Thefe are of a dufky furface, but very bright and fhining when broken, and its conft ruction is very irregular; fome parts of it, where the broad faces of its flakes are feen, appearing of a foliaceous ftiuclure, and others, where their egdes come in view, of aftriated one. Its conftituent particles are fcaly, but longer and narrower than thofe of the French kind. It is much heavier than the French kind, and will neither give fire with fteel, nor ferment with acids ; and calcines a little more flowly than the other to a white plaifter. This is dug in vaft quantities in Derbyfhire, in Yorkfhirc, and fome other parts of England. Hill's Hift. of Foff p. 113.

PARHELIUM (Cycl.) — The frequent appearances of parhelia in cold climates, feem to confirm Defcartes's hypothefis, of their proceeding from icy particles fufpended in the air. See Phil. Tranf. N y 465. Sea. 2.

PARHOMOLOGY, n*j»f*o7ujyi«, in rhetoric, a figure where- in part is yielded to the opponent, and the reft denied : thus, Sume hoc ah judicibus noftra voluntate : neminem illi propwem cog- natum, qitam te, fuijfe, concedtmus : officio tua nmnulla in ilium eztitijfe, Jl'ipendia vss unci fcijfe aUquamdiu, nemo negat fed quid contra tejlamentum diets, in quofcriptus hicejl. Voff. Rhet. I. 5. p. 389. See Concession, Cycl.

PARIETALIA offa. Thefe are fituated on the fuperior, late- ral, and a little on the pofterior parts of the fkull. They are of a larger extent than any other bone of the fkull ; and their figure is nearly that of an irregular convex fquare. They have each an external and convex fide, and an inter- nal and concave one, four edges, one fuperior or fagittal, one inferior or temporal, one anterior or frontal, and one pofterior or occipital. The fuperior edge is the longeft ; the inferior the fhorteft ; in this laft there is a very large fquam- mofe flope, which may be properly named the temporal Hope ; the upper and pofterior edges are indented thro' t'heir whole length ; the anterior edge is indented alio, except at its lower part; and all the lower edge is fquammous, except a fmall portion next the os occipitis. It has four angles, the ante- rior and upper, the anterior and lower ; the pofterior and upper, and the pofterior and lower : the anterior and lower angle ends in a fquammous production, which from it fitua-

tion may be called the temporal angle, or apophyfis. On the outfide above the temporal flope, is feen the moft confider- able portion of the femi-circular plane of the temporal mufcle ; near the upper edge toward the pofterior angle, is a fmall hole called the parietal hole, which is fometimes found only in one of the bones, fometimes in the fagittal future, and in fome fubjeiSts is intirely wanting. In fome this hole alfo goes only to the diploe, in others it perforates both tables. Thefe bones are the weakeft of all the eight that compofe the fkull. The diploe is found between the tables thro' the whole length of the fagittal and occipital edges, and- thro' the upper half of the coronal future. Thefe bones contain a lar^e portion of the brain, form part of the temples, and ferve for the infertion of the temporal mufcles. Winflotvs Anatomy, p. 24..

PARIETARIA, pcltitory of the wall, in botany, the name of a genus of plants, the characters of which are thefe : The flower is of the apetalous kind, and confifts ufually of only four ftamina, which arife out of a cup divided into four feg- ments. This is fometimes of the be!l-fhape, fometimes of the funnel-fhape, and fometimes rotated. The piftil finally becomes an oblong feed, which is contained in the cup of the flower.

The fpecies of parietaria, enumerated by Mr. Tournefort, are thefe: 1. The common parietaria, or pellitory of the wall. 2. The Bafil-leaved parietaria, 3. The leaft annual Portu- gal parietaria. Tourn. Lift. p. 509.

This is a plant of a long time famous in medicine. It is cooling ana abftergent. It is prefcribed in ftranguries, and in cafes of gravel or fmall ftones in the kidneys ; and is an ingredient in many of the fhop-compofitions, intended for thofe purpofes. It is fometimes made an ingredient in de- coitions for clyfters, to be given in nephretic cafes, and ex- ternally is much recommended in the eryfipelas, and for the foftening of hard tumors.

PARISTHIMA, a word ufed by fome authors to exprefs the tonfils. See Tonsils.

PARIUM marmor, in the natural hiftory of the antients, the white marble ufed then, and to this day, for carving ftatues, &V. and called by us at this timejlatuary marble. Too many of the later writers have confounded all the white marbles under the name of the par'tan ; and among the work- men, this and all the othes white marbles have the common name of alabajiers ; fo that it is in general forgotten among them, that there is fuch a thing as alabafter different from marble ; which, however, is truly the cafe. Almoft .all the world alfo have confounded the Carrara marble with this, tho' the^ are really very different ; the Carrara kind being of a finer flrudture and clearer white than the Parian, but lefs bright and fplendid, harder to cut, and not capable of fo glittering a polifh.

The true Parian marble has ufually fomewhat of a faint blue- ifh tinge among the white, and often has blue veins in dif- ferent parts of it. It is fuppofed by fome to have had its name from the ifland Paros, one of the cyclades in the ./Egean fea, where it was firft found ; but others will have it to have been fo called from Agoracritus Parius, a famous ftatuary, who ennobled it by cutting a ftatue of a Venus in it. Hill's Hift. of Foff p. 4.62.

PARK (Cycl.) — A park ought to have three forts of ground in it: 1. Mountainous and barren. 2. Hilly and yet fertile. And 3. Plains that are fufhciently fruitful. The mountain- ous part fhould be well covered with high woods over at leaft a third part of it. The downs and hilly part Ihould have one third part coppices and low woods ; and the plains fhould be at leaft one third part pafture ground, with fome arable or corn land. There fhould be a river contrived to run thro' fome part of it, and a fpring or brook to go through a great part, and at length fall into the river.

Thefe are the natural advantages to be wifhed in spark; but when they are wanting, they are to be fupplied as far as may be by art, as by ponds to preferve rain water, to fupply the place of rivers and fprings and proper plantations, and ex- pofures for the reft ; only the perfon who is to make a park fhould know what the natural advantages are, that he may- take in as many of them as he can. When ponds are to be made to fupply the place of natural brooks and rivers, they fhould be made large enough ; the extraordinary expence in this will be eafily repaid, by breeding fifh in them, and fowl may alfo bf kept in plenty on them. The park fhould alfo be well ftored with trees ; oaks fhould not be wanting in it ; but beech and chefnut are the quickeft of growth, and are eafy to be had : thefe, therefore, fhould be planted in considerable numbers. Apple-trees and plum-trees alfo fhould be planted, as generally thriving very well, and affording good food to the deer, &c.

The beft inclofure for a park is a brick or ftone wall; but as the expence of this is very great, it may be done by pal- ing ; the pales muff, in this cafe, be of found heart of oak ; and fo clofe planted, that no animal of prey can make its way in between them ; and for a farther defence, a good- quick fet hedge is very proper, and fhould be kept in good order. Some part of the mountain and hisrh wood, mav conveniently be made a heronry, and fame part of the

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