Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/905

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being long detained in the Plants, would turn rancid and pre- judicial ro them ; but likewife to imbibe the dew and rain, which contain fait, Sulphur, &c. and to be of the fame life to Plants, that the lungs are to animals. However, the Dr. remarks, that as Plants have not a dilating and contracting thorax, their inspirations and expirations will not be fo fre- quent as thofe of animals, but depend wholly on the alternate changes from hot to cold for infpi ration, and vice i-crfa for expiration. Id. ibid, p 326.

But it is from the roots, that by far the greater part of the nourishment of Plants is derived. Thefe, therefore, are al- ways found to bear a confiderable proportion to the body of the Plant above ground ; the fuperncies of the former being about four tenths of that of the latter. Hence, appears the neceifity of cutting off many branches from a tranfplanted tree ; becaufe in digging it up, a great part of the roots are cutoff". See Halcs's, Veget. Statics, vol. 1. p. 6, 16.

Parafitical Plants, among botanilts. See the article Pa- rasite, C'jcL

Senjitipe Plant, the Englifh name of a diftinct genus of Plants, called by botanifts Mimofa. See the article Mimosa, Suppl.

PLANT AIN-frw, the Englifh name of a genus of trees, called by botanifts Plantago. See the article Plantago, Suppl

Plantain-/w is alfo a name given to the Mufa of Lin- naeus. See the article Musa, Append.

Buckfoorn Plantain, the name given by fome to a. fpecles of Coronopus. See the article Coronopus, Suppl.

Plaktain-j/Jc?, a name by which fome call the Canna and Cannacorus of botanifts. See the articles Canna andCAN-

NACORUS, Suppl.

W^t-Plantain, a name given to feveral fpecics of Ranun- culus, See the article Ranunculus, Suppl. PLANTATION (Cycl.) — As Plantations of trees _ are not only profitable to the owner, as well as ornamental to the country around them, but a national advantage, it may not be improper to give fome directions concerning them. Firft, then, care muff be taken to prepare the ground before trees are taken out of the earth ; becaufe they mould never be fuffered to remain long out of the ground. Care likewife is to be taken not to tear or bruife the roots of the. trees, in raifing them in order to be tranfplanted. When taken up, the next thing to be done is to prepare them for planting ; which is done by cutting off' all the fmall fibres of the roots, and fuch roots as are any wife injured in pulling up, or which

. crofs one another. The downright roots of fruit trees are likewifed to be pruned off, as mould all their irregular bran- ches ; -that when agitated by the wind, they may not rub a- gainft or bruife each other. However, the main (hoots ought by no means to be cut off, as is but too often injudiciouily practifed.

Having thus prepared the trees for planting, they are next to be fixed in the ground ; in doing which, care mull be taken to place them deeper or Shallower, 'according to the nature of the foil j but the beft method of all is to raife a hill of earth, wherein to plant them. They mould be placed as erect as may he, and the earth gently prehed down about their roots ; for it is a fault to make it too hard. Pales or ffakes Should be

.■fixed round them, in order to prevent their being difplaced or blown down by the wind. Wfien the trees are thus planted and Secured, a little mulch

. fhould be hud upon the furface of the ground, to prevent its drying ; and as 10 watering them, it ought to be done with great moderation, nothing being more hurtful to them, than over- watering.

The feafons for planting are various, according to the differ- ent forts of trees, or the foil in which they are to be planted. For fuch trees whofe leaves fall off in winter, the beff time is the beginning of October, provided the foil be dry ; but for

' a wet foil, it is better to defer it to the latter end of February, or the beginning of March ; and for many kinds of ever- greens, the beginning of April is by far the belt feafon ; tho' they may be fafe'ly removed at Midiummer, provided they are not to be carried far. They fhould always be removed in a cloudy moift feafon, by which means they will take root in a few days.

As the method of cultivating- mo ft trees, efpecially garden ones, is explained under their respective articles, there is the

, left reafon to be particular on that head in this place. However one thing more defcrves to be well attended to, as regarding Plantations in general. It is this; that Plantations- fhould be raifed always from trees tranfplanted from nurferies, and never from hedge-rows, or trees of a large fize, becaufe thefe laft feldom come to good account, often dying after continuing a- live for many years.

. Another general rule in regard to Plantations, is, to keep the ground clear of weeds, at leaft for the fpace of feven years ; .for which purpofc it Should be annually dug, or plowed, where that can be done. This will encourage the roots of the trees to extend themfelves, whereby they will draw a larger pro- portion of nourishment. Miller's Gard. Didt. Planting Revcrfc. ,It has been already obferved, that the ■ * branches of trees may be made to ferve initead of roots ; the APPEND,

putting of which in practice is called Planting Reverie. See the article Branch, Suppl.

Mr. Fairchild of Hoxton gives the following directions on this. head. When you have made choice of a young; tree of one Shoot, whether alder, elm, willow, &c. that will eafily take root by layers, the top of the Shoot is to be bent gently down into the earth, there to remain till it has taken root ; the tree all the while refernbling a bow or arch above ground* When the top end is judged to have Struck fufficiently Strong roots, the old root is to be gently raifed out of the ground, and kept in an upright pofition ; after which all the injured parts of the raifed roots are to be pruned off, as well as the buds or fhoots on the item of the tree j taking care to rub over thefe pruned parts with a compofition made of four ounces of tallow, as many of bees-wax, two ounces of ro- fin, and as many of turpentine, melted together in a pipkin ; this to be ufed moderately warm. Vid. Miller's Gardeners Diet.

PLATANOCEPHALUS, in botany, a name ufed by fome botanical writers for the Cepbalantbus. See the aiticle Ce- phalanthus, Suppl.

PLATANUS, the Plane-tree in botany. See the article Plane- tree, Suppl.

PLAY (Cycl.) — See the article Gaming, Cycl.

Duration of Play, in the Dodtrine of Chances is ufed for the probability of the play's ending in a given number of games.

In the Cyclopaedia j under the article Gaming, the two laft problems relate to the duration of Play ; but this difficult fub- ject has been further purfued by Mr. De Moivre in the fe- cond edition of his Dodtrine of Chances, p. 162 — 211.

PLOVER (Suppl.)— Bo/lard-? lover, a name ufed in fome parts of the kingdom for the Capella, or lapwing. See the article Capella, Suppl.

PLOUGHMAN, in hufbandry, the perfon who guides the plough in the operation of tilling, or tillage. See the articles Plough and Tillage, Cycl. and Suppl.

Ploughman'* Spikenard, the Englifh name of a genus of plants, called by botanifts Conyza ; it is likewife called by us Flea-bane. See the article YhKA-bane, Suppl.

PLUM (Suppl) — American Plum, Maiden Plum, or Black Pl UM,names given to a dif tincf genus of plants, called by botanifts Cbryfobalanus. See the article Chrysobalanus, Suppl.

Hog-h^LVM, the Englifh name of a diclindt genus of plants, called by botanifts Spondias. See the article Spondias, Suppl.

Indian date Plum, a name fometimes given to the Diofpyros of Linnsus, and Guajacana of Tournelbrt. See- the article Guajacana, Suppl.

PLUNGER, in Mechanics, a Solid brafs cylinder ufed as a for- cer in forcing pumps. See the articles Forcer and Forcing Pump, Append.

POCCOON, a name by which fome call the Sanguinaria. See the article Sanguinaria, Suppl.

VOCK.-wood, a name fometimes given to Guaiacum, See the ar- ticle Guaiac, Cycl.

PODARIA, in the hiftory of infects, a claffical name compre- hending all fuch infects as have limbs, but no wings. See the article Apteria, Append.

Of this clafs there are two fubdivifions. 1. Such Apteria Pa- daria as have oblong bodies with numerous legs, or more than fix pair : Thefe are the lulus, or gally-worm ; the Sco~ Upendra, or Centipes ; and the Onifcus, or wood-loufe. 2. The Apteria Podaria with Shorter bodies, and lefs numerous legs, or fewer than fix pair ; This fubdivifion contains nu- merous genera, as the Pulex, the Podura or Puceron, the Pediculi of various kinds, the Monoculi, the Acari, the A- ranei, the Scorpio, and a great many others. See the arijS- cles (jALLY-womi, Scolopendra, &c. Suppl.

PODOPHYLLUM, in the Linnaean fyftem of botany, the name of a genus of plants, called by Tournefort Anapodo- pbyllum. See the article Anapodophyllum, Suppl

PODURA, In the hiftory of infects, the name by which Dr. Hill calls the Puccrons. See the article Puceron, Suppl.

The body of thefe animals is Short and roundifh ; the tail is crooked and forked, and amfts them in leaping. They have three pair of legs, which ferve only for walking. The eyes are only two, but each compofed of eight others. Hill, Hiit. Anim. p. 20.

They belong to the clafs of infedts which have limbs, but no wings, and are called by the fame author Podaria.

POET's Rojcwary. See the article Rose MARY, infra.

POINT (Cycl. and Suppl.)— In the Cyclopaedia, a Point is de- fined to be a quantity, which has no parts, or which is indi- visible ; and Euclid's authority is quoted for this. But it ought to be obferved, that the calling a Point a quantity ; or fpeakine; of indivisible quantities, are abfurdities, of which Euclid ~w-as never guilty. As to the demonfl rations of the proportions of mathematical Points to each other, mentioned in the Cyclopedia ; they arc mere paralogifms. Thus in Mr. Robartes's reafoning % fuppofing with him that the chord of a greater circle, touching a fmaller circle at the extremity of its diameter, is = %, and the chord of the fmaller circle cor- 2K re-