Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/236

 P H O

P H O

The fpecies of this genus are the moft valuable of all the gypfums, as burning to the beft and fineft plaifter, but fo far as is yet known there are but two of them. The fine plaif- ter Gone of Montmartre in France, called by us plaijier of Pa- ris Jione and Parget ; and the other the coarfer and fomewhat reddifhkind, common in many parts of England, and called hall plaifier. Bill's Hift. of Foff. p. ua. See the article Parget.

Pholis, in zoology, the name of a (mall anguilliform nih, the back of which is brown, the belly white, and the whole back and fides fpotted, and the (kin foft and not covered with fades, but with a tough mucilaginous matter like the eel. This moft of all approaches to the alauda, and tho' ufually fomewhat larger, yet Mr. Ray doubts whether it really differs from it in any thing effential ; its great diftinction being its colour, which tho' a very obvious, is a very precarious one. Rondelet. de Pifc. p. 20. Rafs Ichthyography, p. 1 35.

PHOLLIDES, a word ufed by the antient phyficians for foft and fungous tumors of the legs, fuch as thofe of people in an anafarca, or leucophlegmacy.

PHONASCI, in antiquity. See Phonascia, Cycl.

PHORtLEA, or Phorbeia, in the mufic of the antients, a name given to a fort of frenum or bandage, applied to the mouths of people who played on the pipe. It was a fort of leather band, which went firft a-crofs the forehead, then behind each ear, and from thence making one or two turns round the head, it pafled over the mouth, where its office was to reftrain the lips from emiting too much breath at once, and caufe them to difcharge only juft fo much as would ferve to inflate the pipe. Simonides describing the trial of fkill between Marfyas and Apollo, mentions this pborbeia or capijlruin, and fome an- tique gems yet remaining among us, have the figure of a Marfyas's head, with the plxrbeia upon it. By the different ftru&ure of the pborbeia, as exprefled on the different coins, we find, however, that there were two fpecies of it, the one was lefs complex, confiding only of a per- pendicular piece down the cheek, and a tranfverfe one, Tun- ing a-crofs the lips, and covering the whole orifice of the mouth, only leaving a hole cut thro' it, at which the mouth- piece of the pipe was to be put in. The other confided of feveral bandages, as at firft defcribed, and the lower tranf- verfe piece of thefe did not come over the mouth, but only bore up the lower lip, in a forcible manner, againft the upper. The old Greek writers diftinguifhed thefe by two different names added to the original word pborbeia ; the firft, or fimple one, was called myomeres; and the other, or more complex one, diemeres : they were both called alfo by Sora- nus, and others, epidefma, and fometimes fimply defma. So- ranus de Epidefmis.

PHORIMOS, a name given by fome authors to reach alum. See the article Alum.

PHORINE, a word ufed by fome authors to exprefs the fkin of a hog; fome alfo underltand it to mean a skin of any kind, extending it even to the human cutis.

PHORMlX, among the antients, the fame with cithara. See the article Cithara, Cycl.

PHORMORAPHIS, in the materia medica, a name often ufed by the later Greek writers, and generally looked on as one of their unintelligible words, or the name of fome drug not known at this time.

If we may guefs at the reft of their unintelligible words, however, by this, it is probable that fomething might be done toward the explaining and underftandingthem, by con- futing the other medical writers neareft their times, and par- ticularly the Arabians.

1 Avifenna mentions the drug called carpejium, or carpejia, which, he fays, was a common fubftitute, in his time, for cin- namon. Galen alfo tells us, that the fame ufe was made of the catpejiuiii in his days; they add defcriptions of the drug, by which it appears probable, that it was either the young {hoots of the cubeb tree, or of fome fuch ftirub. The later Greek writers generally copy their accounts of things from thefe, and they give exactly the fame defcription of the phrmora- phis as thefe do of the carpefia : its ufe, as a fubftitute for cinnamon, is alto mentioned by them. And upon the whole it appears, that it was the name the later Greeks gave to the carpejium, or carpefia, of their predeceffors. It is to be obl'ervcd here, that there is another very different fubftance given in the old Greek writers under the name of carpejium ; and this word is fometimes written carpejium and carpefia. This was a gum refembling myrrh in fmell and colour, but of a poifonous nature : the carpefia here mentioned was, on the contrary, an aromatic medicine. See Carpesia.

P0OS, a word ufed by fome medical writers to exprefs a dif- temperature of the eye, in which there is feen a black circle wholly funounding the pupil.

PHOSCAS, in zoology, the name of a frefh-water fowl of the duck kind, and of the fize of the common wigeon. Its body is remarkably flat ; its beak and legs are blue; its head and neck are of a brownifh colour, variegated all over with numerous triangular black fpots ; and on the top of the head thefe fpots are larger than el fe where, and are of a fomewhat greenim hue; the back, wings, and tail arc of a duflcy brown, I

but the edges of the feathers are pale or whitifh ; the wings are variegated by two long white ftreaks ; the breaft and fides are of the fame colour with the back, but paler ; and the belly of a fine white, but with a few dufky fpots under the tail. Rays Ornithol. p. 289.

PHOSPHORfA, p<w?(.ft*, in antiquity, a feftival in honour of Phofphorus or Lucifer. Potter, Archaeol. Graec. T. 1 . p. 436.

PHOSPHORUS (Cycl.)— Phofphori may be divided into feve* ral kinds ; fome mine of themfelves naturally, as the glow- worm and dates; or adventitioufly, as the flefti of animals, which moft probably arifes from a degree of putrefaction, fometimes too flight to be obvious to our fenfes. Other bo- dies become luminous by attrition, heat, the free action of air; and laftly, by imbibing and retaining the rays of light. Thofe bodies that are luminous by attrition, are, amongft others, fome diamonds, and the hairs of animals ; by heat, feveral forts of gems, and mountain cryftals; from the free accefs of the air, the phofphori of Kraft and Romberg ; from the afpedl of light, the Bolognian luminous ftone, the pre- paration by Chriftian Adolphus Baldwin, of chalk diifolved in fpirit of nitre, as well as feveral others difcovered by the late Monfieur du Fay, who found, that whatever fubftances would by calcination be converted into a calx, or whofe con- crete, from a folution in the acid of nitre, would bear fire enough to become red-hot, thefe bodies were adapted to im- bibe and retain light.

The greater! number of phofphori are of the laft mentioned kind. Some of thefe are natural, others artificial ; but of thefe laft the preparation is fo flight, as not to change die nature of their conftituent parts.

The natural phofphori are either foflile, vegetable, or animal. The foflile are, though very different in degree, fome forts of earths, white fand, lime ftones, ftalactites, and feveral other figured ftones, ifland cryftals, flints, fome fpecies of agates, white arfenic; but no fort of metals, metallic or fulphureous bodies, as jet, amber, except the before-mentioned arfenic. On the other hand, falts imbibe light, provided they are di- verted of every metallic principle ; otherwife not, though as pellucid as poffible. For this reafon none of the vitriols will imbibe light; but other falts will, tho' with a confiderable difference as to quantity ; for fal gem and rock fait imbibe very little ; fea fait, if dry, and in cryftals, much more ; and in like manner, fal ammoniac, fal catharticum and nitre yet more. This power is weak in the natron of the antients, and alum ; but brighteft of all in borax. In the vegetable kingdom we find very few phofphori ; that of dry rotten wood is weak and not lafting; it appears chiefly upon the edges and inequalities of the furface. But this is moft remarkable in the rotten wood of the fir-tree, and fome others, where, in the dark, you fee mining fpots as big as tares ; whereas in full light the whole furface appears alike. Some few barks are luminous, but not confiderably fo ; but no fruits, feeds, or their meals. Cotton and the cryftals of tar- tar, appear very bright, but fine loaf fugar appears the moft luminous of all, both without and within : gums and refins retain no light.

There is a vaft variety of phofphori in the animal kingdom, fuch as the bones and teeth ; to thefe may be added the mells of fifh, egg-fliells, the human calculus, bezoar, and in what- ever parts of animals the terreftrial principle is very predomi- nant. But where there is a confiderable quantity of oily mat- ter, as in the hoofs, horns, and feathers, no light is manifeft. Beccari propofes fome queries concerning the natural phofpho- ri, of which the firft is, In what and how great alight the object ought to be placed ? He tried different phofphori in dif- ferent degrees of light, and found them imbibe moft light from the fun itfelf; next in quantity when the iky was clear; and the leaft in foggy weather. Thefe experiments fhould be made in the open air, and not in a houfe with the glafs- windows {hut; becaufe many bodies appear luminous when the light has- come directly to them, which will not have that appearance when the light has pafled through the glafs. He laftly tried what light they would imbibe from very bright flame, and found that alabafter itfelf, which is faturated more than any fubftance by the fun's rays, imbibed exceedingly little. The next query is, How long thefe bodies fhould re- main in the light to be fufEciently faturated? Four or five fe- conds were found the utmoft length of time required for that purpofe. The other query is, How long the received light will continue in thefe phofphori ? It does not laft the fame time in all ; but continues more or lefs, from two feconds to eight, in proportion to the ftrength of the phofphorus and the quantity of light received.

Phofphori are, it is well known, often produced by art ; fome are made by the maceration of plants alone, and without any fire ; fuch as thread, linnen cloth ; but above all paper. The luminous appearance of this laft is greatly increafed by heat. This is confirmed by two experiments ; the firft is, by expofing the paper, fpread upon an iron-grate to the naked fire, yet not near enough to fcorch it, and then laying a warm brick thereon to retain the heat; by which means it was obferved, that where the paper was not skreened by the iron-grate, it was moft luminous; fo that by the lights and fhades you might diftinguifh in the dark die image oi the

iron-