Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/207

 PEA

PEA

for the trees defigned for dwarfs or for walls ; becaufc they do not let the (hoots grow fo faft and luxuriant. But there are objections againft even thefe, which are of fome confe- quence ; for there' are many kinds of pears which will not do upon them, but will die, or become weak and good for nothino- after three or four years ; and the hard-breaking pears are rendered very unpleafant by being grafted on thefe flocks, while the butter? or melting ones are meliorated by them. And it is to be added, that no fort of pear will thrive upon a quince ftock in a poor or gravelly foil.

pEAR-frwi planted either againft walls, or in efpaiiers, mult not be placed nearer to one another than twenty foot. Pear- trees commonly produce their bloiTom-buds firft, at the ex- tremity of their laft year's {hoots ; the common way of prun- ing; is very prejudicial, therefore, as it takes off the part which fhould bear the fruit, and occafions new fhoots from the fame branch, which will over-fill the tree with wood, the trees fhould always be carefully looked over in fummer, and all the foreright moots taken off; by which means the fruit will not be over fhaded, and the trees will need but little winter-pruning. The feveral forts of fummer pears alt ripen beft in efpaliers, but the winter pears require a fouth- caft or fouth-weft, or elfc an eaft wall. Miller's, Gardener's Diet.

It is faid that crabs and wild pears., fuch as grow in the wild- eft and moft barren clifts, and on hills, may make the richeft, flrongeft, moil pleafant and lading wines that England yields. See Phil. Tranf. N° 477. Sect. 4. *

Indian Pear, a name given by feveral writers to the fruit of a large tree in the Eaft Indies. The bark of this tree is reddifh without and white within, and very fmooth ; the leaves are Imall, thick, and of a pale green ; the flower confifts of three long triangular leave-, which, when fliut up, form a fort of triangular pyramid ; this is of a very difagreeable fmell. The fruit is alfo of a conic figure, its broad part being joined to the pedicle : this is of a woody texture, and of the thicknefs of one's finger ; it divides itfelf into feveral filaments, which run thro' the whole body of the fruit. When the fruit is ripe, its rind or fkin is red, very fmooth and thin, which is contrary to the common courfe of nature in the Indian fruits, to which nature has given very thick rinds, in order to make them able to bear the great heats they are expo fed to. The infide of this fruit is full of a white, foft, and fweet fub- ftance, which is ufually fcooped out with a fpoon, and is of a very pleafant tafte : within this fruit there are feveral fmooth, black, kernels, like thofe of our common pears. When this fruit is mellow, the pulpy part of it falls away from the fibres, and they remain hanging to the pedicle for a long time.

'C'bio Pear. See Ci-no Pear.

PEARCH, in ichthyology. See Perca.

PEARLS (Cycl.) — Mr. Reaumur was very happy in his con- jectures as to the nature, origin, and differences of pearls, founded on what he faw in the coarfe pearls of the pinna ma- rina* He very judicioufiy obferves, on that occafion, that ofa-n the leaft valued things are thofe which moft of all ex- plain, even by their imperfections, the manner of formation and the true hiftory of the moft perfect.

The pearls found in the pinna marina, are of two kinds; fome being white and glofly, like the common pearls, and others brownifb, reddifh, or blackifh. He very well ob- ferves, that they are all formed of extravafated juices ; which have made their way out of broken vefiels, and therefore are the effect of a diftempered irate of the animal, and are form- ed in the manner of bezoars in the ftomachs of animals, or the {tones in their bladders. The inner furface of the fhell of the pinna is of a filvery white, or of the nature of mo- ther of pearl, to a certain depth, after whicfa.it is reddifh or brownifh. Thefe are the two colours alfo of the two forts of pearls.

The fliclls of fifties Mr. Reaumur fuppofes, are formed mere- ly like thofe of fnails, of a vifcous matter, fecreted from their bodies, which hardens by degrees into a fort of ftony tex- ture ; and that the pearls in this fifh owe their colour to their being formed of the extravafated juices of the white or the brown parts of the (hells. The juices of thefe parts are fe- derally intended to form their part, and the bed or plate of ftielly matter formed of either, in its proper and natural itatc, could be onlv white or brown, as the liquor was co- loured; and, confequently, fo muft be the diftempered pro- duction of pearl. The breaking of the vefiels of the inner pearly coat, both in this and other me Is, feems much more frequent than that of thofe of the browner external part ; and it is eafy to fee, that this may mucli eafier make its way into the hollow of the ihell than that from the more outward part ; but it is alfo eafy to fee that, provided the brown juices of this outer part could be extravafated, and find their way into thp hollow of the fhell, they could only form pearls of their own colour.

In this ihell of the pinna marina, the white or pearly inner part is formed of a vaft number of flat plates or beds, laid one upon another ; and the brown external part is formed of tranfverfe fibres, not formed into fuch plates, but running in long ftria?. The pearls of the two different colours have al- Suppl. Vol. II,

fo this difference in their ftructure ; not but that both the one and the other are compofed of concentric beds or plates, but thefe are much lefs diftinguifhable in the brown than in the white ones ; and each of them may in thefe be Ccen to be made up of filaments exactly as the brown part of the fhell, to the extravafated juices of which they owed their ori- gin, and whofe texture therefore they could not but emulate. Mem. Acad. Par. 1708.

Pearls, in commerce, increafe in value as the fquare of their weight ; thus, the price of a pearl of one carrat being fettled at 8 s. to find the price of a pearl weighing fix carrats : firft find the fquare of fix, viz. 36; which multiplied by 8 gives 288 /hillings, or 14 1. 8 s. the price required. Jeffries on Diamonds, p. 64.

Pearl, in ichthyology, a name given by us in the parts about London, to that fifh which is called in Cornwall, and other parts of the weft of England, lug-a-leaf ; it is the rhombus lavis of the generality of authors ; and, according to the new fyftem of Artedi, it is a fpecies of the pieuraneStes, dif- tinguifhed by the author by the name of the fmooth bodied pleu- rorie&'es, with the eyes on the left fide. See the articles Rhombus, Pleuronectes, and Lug-a-Leaf.

FEARL-barley affords to the microfcopic obferver, a peculiar kind of mite worthy attention, and very different from the common fpecies. The bodies of thefe have fome brown marks upon them, and have not fuch long hairs as the com- mon mites have ; the hinder part of the body alfo is of a different make. They have eight legs; and before the head there ft and two weapons twice as thick as the legs, and of about half their length: thefe are divided toward the ends with joints like fingers, and thefe have at their ends a fort of nails formed with fbarp and crooked claws ; and one of the longeft joints is ferratcd at the edge like a faw. Thefe wea- pons ferve not only as arms and hands to feize hold of things, but they alfo ferve as a defence; for as foon as any danger threatens the creature's head, it erects them both, and makes them meet and fold into one another over the head, as we can join our hands and fingers together in the fame erect pofture. Phil. Tranf. N° 222.

Pearl colour, in glafs. This beautiful colour is given to glafs in the following manner: Put tartar calcined to a whi tenets into putrified cryftal, while in fufion, at feveral times, in fmall quantities, mixing it well every time, till the glafs is be- come of the defired colour ; and when it is, work it as quick as can be, for it is a colour that is quickly gone. Ner?$ Art of Glafs, p. 103.

PEAiiL-f/Jw/g, in the north of Ireland. See an account of it in the Philofophical Tranfactions, N° 198.

PEASE, pi/a, in botany. See Pisum.

We have feveral forts of peafe cultivated for ufe in the gar- dens about London and elfe where ; and as many people are defirous of having them very early, it is a common practice to raife them on hot beds. The method of doing this is, to fow the peas under warm hedges or walls. In the middle of October, when the plants are come up, their ftalks are to be kept earthed up, and thus they are to remain till the be- ginning of January, or even till February, covering them againft the fevere frofts with ^w-hauJm, or other light co- vering. In January or February, there muft be made a moderate hot-bed ; the dung muft be laid about two foot thick, and carefully beat down, and covered about fix inches deep with light frefh earth ; and when the frames have been fet on about four days, the plants muft be planted in the earth, at about a foot diftance, in rows, and placed in each row at about two inches one from another. They muft be watered and fhaded til! they have taken root, and then they muft have as much air as may be ; and when they begin to fruit, they fhould be watered more frequently than before, which will occafion their producing a larger quantity of fruit.

The common dwarf pea is the fort always ufed on this occa- fion, as all the reft ramble too much in their ftalks. The firft fort of fea to be fown to fucceed thofe on the hot- beds is, the hotfpur ; of which the gardners reckon three or four forts, which differ very little from each other; but that called the mailers hotfpur is ufually preferred to the reft. Thefe are to be fown in October, as thofe intended for the hot-bed, and treated every way in the fame manner ; but in fpring thefe are fubject to be deftroyed by flugs and other vermin ; the beft method of deftroying which is, 10 flake a little lime, and throw over the earth among the plants. For fear of this crop mifcarrving by the feverity of weather, it is always proper to fow two others after this, at the diftance of a fortnight each ; and after this there fhould be no others fowed till the end of January; and after thefe there fhould be others at the beginning and end of February. To fuc- ceed thefe, which will fupply the table with early peafe, the Spanifh morotto, which is a large pea, and a very plentiful bearer, fhould be fowed in rows on a clear plat of ground ; the rows fhould be two foot and a half diftant, and the feafe dropt at an inch or two afunder : thefe muft be all very care- fully covered two inches deep with earth, and the rooks, mice, &c. prevented from getting at them. A fortnight after thisanother fpot fhould be fowed with this or fome other B b b large