P Y R 



P Y R 



28. P. Myconi. Tongue-leaved Yellow Feverfew. 

 (Chryfanthenuim Myconi; Dalecli. Hid. S73. I^inii. Sp. 

 PI. 1254. Willd. Sp. PI. V. 3. 2148. Ait. Hort. Kcw. 

 V. 5. 96. Jacq. Obi', fafc. 4. 10. t. 94.) — Leaves tongue- 

 ftiapcd, obtufe, toothed, clafping the much-ljcanched ftem. 

 Radiant florets numerous, roundidi. — Native of fields in tlie 

 fouth of Europe ; a hardy annual with us, but preferved 

 for the fake of variety, rather than ornament, the flowers 

 being inferior in fize and fplcndour to our wild Cbryfimlbc- 

 mum fcgetum, while the leaves refcmble thofe of C. Ltu- 

 canlhenuim. The plant liowever is very different from both 

 thofe, and a true Pyiethriim, akin to the laft defcribcd, the 

 feed having a very evident membranous crown, as Will- 

 denow, copying Linna;us, mentions ; yet he lUll left this 

 fpecies where he found it. Our predece<ibr, the excellent 

 Jvlr. Wood, has corredled this error. (See Chuysantiie- 

 MUM, at the end.) We venture likewife to correft the 

 fpecific name, which authors have copied incorrectly from 

 Dalechamp. He calls the plant Myconi, after its difcoverer 

 Myconus. The Jlem is very much branched. Lea-ves 

 fimple, an inch and a half or two inches long, fmooth. 

 Flo-wrrs on long folitary ftalks, at the ends of the branches, 

 bright yellow, an inch wide ; tiieir radiant florets numerous, 

 crowded, fliort, of a roundidi or oblong fhape. Seed-crown 

 large, jagged, and fringed. 



PYRETICS, formed from ■zv=iro:, fever, of 'a-u^, fire, 

 medicines good againft fevers. 



PYREXIA, in Medicine, from 'TtufiTo:, fever, a term 

 ufed by Dr. Cullen to fignify feverifh aftion generally, 

 whether idiopathic or fympathic. The fame writer alfo 

 ufed the term as the denomination of his firit clafs of difeafes, 

 including fevers and inflammations. See his Nofol. Method, 

 clafs I, Pyrexidt. 



PYRGI, or PvRGOS, in Ancient Geography, a town of 

 Italy, upon the coaft of Etruria ; placed by Ptolemy 

 between Caftrum Novum and Alfum, and faid by Livy to 

 have been a Roman colony. — Alfo, a town of the Pelo- 

 ponnefus, in Meffenia. 



PYRGO, in Geography, a fea-port town on the S.E. 

 coaft of the ifland of Santoria. N. lat. 36° 26'. E. long. 

 zf 38'. 



PYRGUS, among the Romans, a dice-box of the fhape 

 of a niodius, open above, and having a great many flielves 

 or partitions within it ; fo that when the dice were thrown 

 into it out of the fritillum, they were thereby overturned 

 many times before they could reach the bottom, in which 

 there was an opening for them to fall through upon the 

 table. 



PvRGU.';, in Botany, a genus of Loureiro's, Fl. Cochinch, 

 120, which Mr. Brown, Prodr. Nov. Holl. v. i. 533, re- 

 duces to Ardisia, fee that article. The name is taken 

 from itv^ya:., a turret, alluding to the conical fhape afTumed 

 by the converging ftamens. 



PYRHOPOECILOS, in the Natural Hiflory of the An- 

 dents, a ftone fo called from its having a great many fpots 

 of the colour of fire. 



PYRIATERION, a word ufed by the ancients to ex- 

 prefs a fweating room. 



PYRIATOS, a word ufed by fome authors to exprefs a 

 brick when heated, in order to be applied to the body 

 wrapped up in a cloth by way of a dry fomentation. 



PYRICAUSTUM, a word ufed by medical writers to 

 exprefs a burn or fcald. 



PYRICUBIUM, in Natural Hiftory, the name of a 

 genus of foflile bodies, ufually comprehended, with many 

 others of very different figure and flrufture, under the 

 general nzme pyrites. 



Vol. XXIX. 



The diftinguifliing charaftcrs of the pyricubia ara thefe ; 

 they are compound, inflammable metalhc bodies, of a cubic 

 I'igure, or refembliiig a die, being compofed of fix fides. 

 Of this genus there are only two known fpecies. Hill. 



PYRIFORMIS, in Anatomy, a mufcle of the thigh, 

 flattened and triangular in its figure, fituated at the back of 

 the pelvis, and extending from the facrum to the great 

 trochanter. The poflerior furface is covered by the gluteus 

 maguus, and partly by the medius. The anterior is partly 

 in the pelvis, partly on the outfide of the cavity. Within 

 the pelvis it correfponds to the reftum, the fciatic plexus, 

 and the hypogaftric vcflcls : externally to the cavity it 

 covers the gluteus minimus, the os innominatum, and the 

 capfule of the hip. The upper edge correfponds to the 

 fciatic notch, and the gluteal artery ; it then lies clofe to the 

 gluteus medius. The inferior edge correfponds to the leffer 

 lacro-fciatic ligament, and then is parallel to the geminus 

 fuperior : it is at firfl feparated from the latter mufcle by 

 the great fciatic nerve, and afterwards approaches to, and 

 is united with it. 



The balls of the pyriformis is attached to the fide of the 

 anterior furface of the facrum, in the intervals of the facral 

 foramina, to thefe foramina at their outer parts, to the an- 

 terior furface of the great facro-fciatic ligament, and to the 

 poflerior and upper part of the os innominatum. The 

 mufcle proceeds from within outwards, and rather down- 

 wards, pafles out of the pelvis at the great facro-fciatic 

 foramen, gradually diminifhes, and terminates in a fmall 

 tendon, fixed to the upper part of the internal furface of the 

 great trochanter. 



The attachment of this mufcle to the great trochanter is 

 by means of a tendon, the lower edge of which is con- 

 nefted to that of the fuperior geminus. This tendon ex- 

 pands into an aponeurolis, which, after extending on the 

 front of the mufcle, enters into its fubftance. The flefhy 

 fibres arife from the parts mentioned above ; and are fixed 

 in all direftions to the tendon. Sometimes a portion of the 

 fciatic nerve pafTes through a flit in the mufcle. 



When the thigh is extended, the pyriformis will rotate it 

 outwards ; but when it is bent, it will aft as an abduftor. 

 If the thigh is fixed, it will move the pelvis in an oppofite 

 direftion. 



PYRIPHLEGES, a word ufed by the old writers in 

 medicine to exprefs a perfon labouring under an extreme 

 degree of a febrile heat. 



PYRIPLACIS, in Natural Hiflory, the name of a 

 genus of pyritae, the charafters of which are thefe : they 

 are compound, inflammable, metallic bodies, found in loofe 

 detached mailes of a fimple and uniform, not ftriated in- 

 ternal flrufture, and are covered with an invellient coat or 

 crufl. 



Of this genus of foflils there are three known fpecies. 

 Hill. 



PYRIPOLYGONIUM, the name of a genus of 

 foflils, the charafters of which are, that they are compound 

 metallic bodies, of a regular figure, confifting of twelve 

 planes. 



There is only one known fpecies of this genus, though 

 fubjeft to great varieties in its appearance ; and this has 

 been by authors hitherto confounded with many other bodies 

 of a very difterent nature and figure, under the general name 

 pyrites. 



It is not unfrequent in Cornwall and Devonfliire ; but is 

 much more common in Germany. Hill. 



PYRITES, Sulfure metallique, in Mineralogy and Chi- 

 miflry, a name given to certain ores which contain a large 

 quantity of fulphur, and have a metallic luftre. The Greek 



K word 



