Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/286

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PORTOISE, aboard a fhip, is the fame with port-la/?, or the. gunwale ; and as they fay the yard is down a port-lajl, when it lies down on the deck, fo for a (hip to ride a portoife, is to ride with her yard a port-lajl, or ftruck down to the deck.

PORTORARIUM, in anatomy, a name given by fome au thors to the duodenum.

PORTULACA, purfelain, in botany, the name of a genus of plants, the chara£ters of which are thefe : the flower is ro- faceous, or compofed of feveral leaves difpofed in a circular form. The cup confifts of one leaf, and is bifid ; from this arifes the piftil, which afterwards becomes, together with the cup, a fruit or feed-veflel of an oval form, and ufually contain- ing very fmall feeds: this feed-veflel has two mclly fubftances

. at its top, the outer of which has been the bifid part of the cup ; the inner is no other than the piftil enlarged ; thefe fe- parate tranfverfely when the feed is ripened, the lower part of the cup ftill remaining fixed to the ftalk. The fpecies of purfelain, enumerated by Mr.Tournefort, are thefe: I. The broad-leaved, or garden purfelain. 2. The narrow-leaved, or wild purfelain. 3. The broad-leaved gar- den purfela in, with gold yellow leaves. 4. The broad-leaved {ea-purfc/ain, with beautiful red flowers. 5. The red-flower- ed procumbent purfelain of Curaflb, with long, thick, and Alining leaves, b. The procumbent purfelain of Curaflb, with leaves like thofe of the caper's bufh and red mofly flowers. 7. The taller upright woolly purfelain of Curaflb, with leaves like thofe of kali, and pale red flowers. 8. The woolly pro- cumbent purfelain of Curaflb, with beautiful red flowers, and feed-veflels fomewhat pointed at the ends. 9. The wool- ly, procumbent, kali-leaved Curaflb purfelain, with feed-vef- fels hollowed at the ends.

The feveral fpecies of purfelain^ may be known when not in flower, by their having thick and flefhy leaves placed alter- nately on their ftalks. Tourn. Infl\ p. 236.

PORTUGALLICA terra, earth of Portugal, in the materia medica, the name of a fine aftringent bole, dug in great plenty in the northern parts of Portugal, and efteemed a re- medy againft poifons and venomous bites, and good in ma- lignant fevers. Whatever may be its virtues of this kind, however, it is manifeftly an aftringent of the very firft clafs, and is ufed with great fuccefs in fluxes of all kinds. It is well known in fome parts of the world, befide the kingdom where it is produced ; but is not known in the Englifh (hops. The cheapnefs of our fophifticated bole armenic, having excluded this whole valuable clafs of medicines from our practice. The characters by which the Portuguefe earth is known from

. the other red boles, are thefe: It is of a clofe, compact, and regular texture, confiderably heavy, and of a fine florid red,

- of a fmooth and fhining furface, eafily breaking between the fingers and a little ftaining the hands. It adheres firmly to the tongue, melts freely and readily in the mouth, and has a ftrongly aftringent tafte, but leaves a little grittynefs between the teeth. It does not ferment with acids, and fuffers fcarce any change of colour in the fire. /£'//'s Hift. of Foil*, p. 13.

PORTUMNALIA, among the Romans, a feftival in honour of Portumnus, which was celebrated on the feventeenth of Auguft. Pitifc. in voc.

PORUS, {Cycl.) in natural hiftory, a name given by authors to a peculiar kind of foflile coral, of which there are many dif- ferent fpecies; thefe are all of a beautifully laminated ftruc-

' ture, and feem allied to the mycetitas or fungitse : they are fel- dom found loofe, but ufually bedded in hard marble, and with their pores filled up with fparry or mineral matter. See Tab. of Fofl*. Clafs 7.

Porus cervinus, in natural hiftory, a name given by authors to a fpecies of fea-plant, found among the rocks In the coral fifheries, and in other places. It grows at different depths, and feems to adhere to the rocks by a Ample bafe, having no root, nor any thing in the place of one. It is branched in fuch a manner, that with the help of a little imagination it has been forced into the refemblance of a flag's horn. Its height is about an inch and half, often lefs when newly taken out of the fea; it is of a fine fnow white colour, but when it has lain fome time to dry, it becomes of a dufky yellow. It is very thin, perfectly tranfparent, and feems com- pofed of feveral fine membranes. When examined by the microfcope, an admirable ftruclure is difcovered in it : the whole being compofed of a membranous matter, in which are an infinite number of holes, and all thefe arranged into regular lines.

Count Marfigli has diftinguifhed this, which is the common kind of porus cervinus, or buckthorn p:rus, by the name of minor, in order to prevent its being confounded with another lefs common kind, which Ferrante Imperato has defcribed under the name of porus cervinus.

This larger kind is found alfo growing on the rocks in the co- ral fifheries ; but it always is found at great depths, never near the furface, as the other often is. It grows to the rock ■ by a fmall bafe, and from thence rifes to a fhort trunk, which fpreads itfelf out into feveral flat branches, divided every where into two, as thofe of mod of the fca-fucufes are ; and thefe are fo expanded as to form what people imagine, a refemblance of a flag's horn. This grows to a little more than two in- ches in height, and is of a beautiful pale yellow, or ftraw co-

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lour, even while growing, and looks glofly and fhining, as if covered with a thin coat of varnifh. It is as thin as the fineft paper; and when viewed by the microfcope, is found to be of a particular texture. It is fometimes found growing to the fhells of fea-fifhes; but of thofe only which live in great depths of water. Count Marfigli has given elegant figures both of this and the fmaller kind, not only in their natural ftate, but as they appear to the microfcope. Marfigli, Hift. de la Mer.

POSCENIUM, or Postscenium, among the Romans, the back part of the theatre, where the actors retired to undrefs tbemfelves. Danet. in voc.

Poscenium was fometimes ufed to fignify a lady's drefting-room, where the paint and wafhes were kept and ufed, and where men were not allowed admittance. Pitifc. in voc. See the article Parascenium, Cycl.

POSIDIA, ntwn^a, in antiquity, a feftival in honour of Nep- tune, called n«r ( Xy. potter, Archasol. Gra^c. 1.2. c. 20. T. 1. p. 426.

POS1DIUM, Tlo<7i;ha>, in chronology, the feventh month of the Athenian year. It confifted of thirty days, and anfwered to the latter part of our December and the beginning of January. See Month. It had this name from the feftival Pofidonia celebrated in it.

POSIDONIA, n«™W, in antiquity, the fame with pofidia. See Posidia.

POSIQUIT, in natural hiftory, a name given by the people of the Philippine iflands to a fmall bird very common among them, and approaching to the nature of the canary bird, but fmaller, and wanting its harmonious voice.

POSITI, among the Romans, an appellation given to the dead when placed at the door with their feet outwards, till the time of their interment. See Burial and Burying. Hofm. Lex. in voc.

POSITION, pcfitio, in mufic, is ufed for the putting down the hand in beating time. See Thesis.

POSITIONAL libel. See Articulated libel.

POSSE SSlOfratris, in law, is where a man hath a fon and a daughter by one woman or venter, and a fon by another ven- ter, and dies, if the firft fon enters and dies without iffue, the daughter fhall have the land as heir to her brother, although the fecond fon by the fecond venter is heir to the father : but if the eldeft fon dies without iffue, not having made an ac- tual entry and feifin, the younger brother by the fecond wife, as heir to the father, mail enjoy the eftate, and not the filler. 1 Inft. 11, 15. Terms of Law.

POSSESSION (Cycl.)— Possession, in mining, is the right to a meer of ground, which the miners enjoy, by having ftones upon that ground ; and it is taken generally for the ftones them- felves ; for it is the ftones that give poffefjim. Houghton's Compl. Miner in the Explan. of the Terms.

POSSUM, a name by which many have called the opojjum. See the article Opossum.

POSTERIOR {Cycl.) — Posterior penis, in anatomy, aname given by many authors to a mufcle more generally known at this time by the name of the creclor. See Erector.

POSTICUM, in architecture, the poftern gate or back door of any fabric.

POSTOMIS, among the antients, a barnacle or iron inftru- ment fixed on the nofe, or put into the mouth of a horfe to make him quiet. Pitifc. m voc.

POSTURE (Cyd.)— Postures of the hdy. The continued unnatural pojfures of the body, are the occafions of many very unhappy effects In the human frame ; crookednefs in fhape, is very frequently the confequenceof them. See Distortion. And it is no uncommon thing to fee fchool-boys, who are forced to be continually bending to write upon their knee, or upon a low form, very terribly afflicted by means of the compreffion which that unnatural and continued pqflure has given the lower part of the breaft and the vifcera contained in the eprgaftrium ; and particularly thofe unhappy youths, who, from being fhort-fighted, are expofed to a greater de- gree of ftooping than the reft, have been found terribly afflict- ed with diforders of the breaft and of the lower belly. On applying for relief in thefe complaints, the phyfician ufual- ly forgets to enquire into the caufe, and hearing nothing of the continued bending po/lure of the body, which is the occaflon of all the diforders, the medicines he gives prove ineffectual with fome, and with others greatly heighten the diforder. But when the prefcriber will be at the pains of informing him- felf of the caufe in thefe cafes, and forbid the continuance of the po/lure which has been the fole occafion of them; nature alone will often make the cure, or if not alone, yet very of- ten with this caution the methods will prove fuccefsful, which were ineffectual, or even hurtful without it. Other fchool-boys have been found fubject to feveral diforders of the head, the breaft and eyes, and to many other com- plaints from which the ufual methods in the like cafes have been found wholly ineffectual to relieve them ; or if they have been cured from time to time, they have been always found fubject to relapfes : and in many of the fchools of France, no remedy could be found for thefe complaints, till Mr. Winflow found, on enquiry, that it was a common cuftom among thefe youths to fleep all night with their heads thrown back, 2 and