Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/314

 P T A

P T E

Fuchfius confeffes he does not underftand, yet is plainly no ; other than a barbarous term formed by thefe Grecians on the word fcabiofa, the Latin name of the plant. The change between fcabiofa and fcampiufa isfcarce anything, for the common cuftom of the Greeks of thefe times, was to change the Roman b into mp, in the words which they adopt- ed from that language. Pelagonim, c. 300. PSOROPHTHALMIA, (Cyd.) a name given by the antients to a fcorbutic diforder of the eye-lids, very troublefome to the patient, and cured with difficulty. PSUCHAGOGICA, a word ufed by the antients to exprefs fuch medicines as were ufed in apoplexies and faintings, to re- cal life. PSUCHROTROPHON, in the materia medica of the antients, a name given to 3 plant often recommended, but not perfectly underftood as to what fpecies it means. It is the fame plant called ceftrum by the Greeks, and has this firft name only be- caufe of its growing in moift places ; the word being formed of the Greek fudges, moift, and t ? =<?o, to nourifli or caufe to grow.

Diofcorides has opened a way to great perplexity, by faying that this is the plant which the Romans in his time called the betonica, or ferratula, and fometimes rofmarinus. The Romans feem from this to have been at that time very indeterminate jn their names ; but by the defcription it appears clearly, that the rofemary which we know by that name, could not be meant ; and the queftion lying wholly between the betony and ferratula, is decided in favour of the latter by the defcription, which, as it ftands in Diofcorides, gives the plant the leaves of the oak. This may feem at firft fight not to make much in favour of the ferratula ; but the refcmblance is explained, as this author exprcfly does, to confift only in their being very deeply finuated, and finely notched, or ferrated, all round. The ferratula of our times feems plainly meant as the plant. So that this plant we are to obferve, is the ceftrum and pfeu- chrotrophon of the Greeks, and the betonica, or vettonica, as well as the ferrata of the Romans ; and is fometimes called rofmarinus. Apuleius feems to perplex the whole affair in a flrange manner, by faying, the betonica has leaves like the docks, and very large ; but we are to obferve, that he miftakes the betonica and britannica for the fame plant, and fays, that the betonica, or britannica, was called cejlrum, &c. by the Greeks. The reafon of his faying the leaves are like thofe of the dock, is eafily feen after this ; fur Diofcorides fays fo of the britannica, and that very juftly ; it being only the com- mon great water-dock, or hydrolapathum. Pliny has fome- where run into the fame error, of giving leaves like the dock to the betonica ; but the fource of his error is plainly the fame. We may obferve from this, however, that very little depen- dence can be had on the accounts thefe authors give us of plants. PSYt'HROLUSIA, a word ufed by medical writers to exprefs

cold bathing. PSYCTICA, a term ufed by medical writers to exprefs cooling

remedies. PSYDRACIA, a term ufed by medical writers to exprefs fmall tubercles on the head, which refemble puftules, and after a little time corrode and eat through the fkin. PSY'GMATA, a name given by phyficians to all refrigerating

medicines, external and internal. PSYLLIUM, fieaxv.rt, in botany, the name of a genus of plants, the flowers and fruit of which are like thofe of the plantain's, but the ftalks are ramofe and folsaceous. The fpecies of pfyllium, enumerated by authors, are thefe : 1 . The pfyllium of Diofcorides, or Indian pfyllium, with jagged leaves. 2. The great upright pfyllium. 3. The larger pro- cumbent pfyllium. 4. The leflcr pfyllium of Cafpar Bauhine. Tourn. Inft. Bot. p. J28.

The feeds of pfyllium are recommended by many in jaundices and dyfenteries; but the prefent practice receives it only as a mucilaginous feed. PSYLON, in ichthyology, a name given by Ariftotle, and many other of the old Greek writers, to the tench, or cypri- nus niger. See Cyprinus and Tinca. PTARMICA, fneczewort, in botany, the name of a genus of plants, the characters of which are thefe : the flower is of the radiated kind, the difk being compofed of flofcules, and the outer circle of fe mi- flofcules ; thefe are placed upon the em- bryo-feeds, and are contained in a fquammofe cup. The em- bryos afterwards become flender feeds. To this it is to be added, that the leaves are either only denticulated at the edges, or elfe divided into large broad fegments, wholly different at firft infpecrion from the leaves of yarrow. The fpecies of ptarmica, enumerated by Mr. Tournefort, are thefe : 1. The common tiarmica, with long ferrated leaves and white flowers. 2. The common ptarmica, with double flowers. 3. The Alpine ptarmica, with leaves partly whole, and partly ferrated. 4, The low dwarf ptarmica, with leaves divided in the manner of thofe of wormwood. 5. The Cretric flirubby ptarmica, with the appearance of the fantolina. 6. The purple- flowered tawny-leaved Alpine ptarmica. 7. The yellow- flowered fweet fcented ptarmica. 8. The yellow fweet ptarmi- ca, with long and thick tufts offlowers. Q.The Alpine ptarmica, with deeply divided leaves. 10, The feverfew-leaved Alpine

ptarmica. 1 1. The tall Alpine ptarmica, with yellowifh white flowers. 12. The other Alpine ptarmica, with lefs compact flowers. 13. The elecampane-leaved Virginian ptarmica. Tourn. Iirft. p. 496.

The common ptarmica is frequent in our meadows, and flowers in June and July. The leaves are of an acrid tafte, and are fometimes added to fallad inftead of crefies, or the garden-tar- ragon. When dried and rubbed to powder, they are a good fternutatory; they are not over ftrong, but occafion a continued fneezing, which draws out a great deal of phlegm by the nofe. The root has the fume virtue more ftrongly.

PTELEA, in the Linna?an fyftem of botany, the name of a di- ftincr. genus of vegetables, the characters of which are thefe: that the cup is the perianthium, c'ivided into four fmall feg- ments. 1 he flower is compofed of four petals, which are of an oval figure, and pointed at the ends; thefe are flat, larger than^the fegments of the calyx, and fpread wide open. The ftamina are four pointed filaments. Theamheraeare roundifh. Thegermen of the piftil is orbicular, but fomewhat com- prefled. The ftyle is fhort The ftigmata are two, and are acute. The fruit is a circular membrane, placed perpendi- cularly, with a cavity in the middle, which contains the feed,- which is fingle and oblong. The fruit of this genus is ex- tremely like that of the elm, but the ftamina are wholly dif- ferent. Linncei, Gen. PI p. 49.

PTERIDION, in botany, a name ufed by fome authors for a fmall kind of fern common in damp places. Ger. Emac. Ind. 2.

PTERIS, in botany, the name of a genus of ferns, the cha- racters of which, according to Linnseus, are thefe: the fruc- tifications are difpofcd into a line, which furrounds the whole margin of the under part of the leaf. In this difpofition the pteris evidently differs from all the other capillary plants.

PTEROPHCENICUS Indiarum, in zoology, a name under which Niercmberg has defcribed a bird, which he fays is call- ed by the Spaniards there commendackxa, remarkable for the rednefs of the upper part of its wings.

It is of the fhape and fize of the ftarling, and not unlike it in colour, but for the Angularity of the upper part of their wings, which in one part of their lives are of a yellowifh or orange colour, and in the reft red. They are kept in cages and learn to imitate the human voice: they feed on vege- tables, principally Indian corn, and are common as well in the colder as in the hotter climates; flying in large flocks, and often doing great damages to the people. They build in trees and are eaten there; but are no very valuable bird. Ray's Ornithology, p. 302.

PTEROSPERMADENDRON, in Botany, the name of a ge- nus of plants, eftablifhed by Dr, Amman. The name is derived from the Greek dyer, a wins:, <"» r 7*«, feed, and Mjsrf, a tree, to exprefs a tree with alated "feeds. The characters of the genus are thefe : the flower is of the rofaceous kind, confifting of feveral petals arranged in a cir- cular order. From the cup of the flower there arifes a piflil, with an embryo fruit, which finally becomes a woody feed- veffel of the fhape of a pod, which, when ripe, opens at the end, and is feen to be divided into five cells, containing alated feeds.

Of this genus the author defcrihes two fpecies. The firft has leaves like the cork-tree, angulated and hoary underneath, and white flowers : the other has auriculated leaves, and a large flower and fruit. The firft of thefe is mentioned in Petiver's mufeum, N Q. 049. under the name of a tree from Cham- pana, with a woody fruit, containing alated feeds : and the other feems to be the tree called filda, in the Hortus Mahba- ricus, Vol. VI. T. 58.

Befides thefe two fpecies, the author fufpefls there are four others, which have not yet been fufEciently examined in their various flates, to determine whether they are properly of it or not. Thefe are,

I. The poplar-leaved tree alcea, called the green ebony at St. Helena, and by the hnglifh Uachvood and ebony, Pluk. mant. T. 333- 2 - The tree alcea, with large red flowers, and with leaves like the black poplar, hoary underneath, called by the Englifh redwood, ejufd. 7. The quinquecapfular alcea of Florida, with bay-like leaves, lightly crenated, and with alated feeds. And, 4. a tree with pentangular fruit, and alated feeds, col- leaed by Dr. Houfton, at La Vera Cruz. Afl. Petropol. Vol. VIII. p. 2.8.

PTERYGIUM, (Cyd.) in anatomy and furgery, a preternatu- ral membrane, formed externally upon the coats of the eve, and extending itfelf over the cornea and pupil, and obftruct- ing the fight. Sometimes this pellicle or membrane appears red, and is then called panmts.

It ufually arifes in the angles of the eyes from the temples to- ward the nofe, and fometimes from above or below, extend- ing itfelf by degrees over the pupil. Sometimes it only ad- heres to the cornea by a few flender fibres, and fometimes it is extended over the whole eye, and is every where firmly and intimately attached to it ; and in this cafe the cure is rendered very difficult.

If the patient's conftitution, or a beginning inflammation re- quire it, bleeding and bliftering are proper in this cafe; and when the membrane is but thin, gentle efcharotics may per-. 6 form