II 



PYRAMI8. 



PYROKTHITK. 



511 



Siylimu has 6 nont nwciM. Thry an found in the Wat Indie., the 

 Philippic*., od the Gaispagoa. 



[itmimt it a fotail grnu* with 75 tpecirc Principally from the 

 Lower Silurian of North America and Europe. 



JlaerorMItu b foMil. and hat 12 pecie*. They are found in the 

 IWvooian and Carboniferous Rock*. 



For the other genera aw CIIKMMTXIA. OIIX>TOKIA, KCLIMA. 



I'Y ItAMIS, a genus of Gasteropodout Molltuca; also of A calepha. 

 



PYRARGILLITE, a Mineral occurring in four-aided prisms, with 

 benlWd edge* and massive ; frequently traversed by chlorite. Colour 

 black or blue; in the former oae shining, iu the latter dull. Emit* 

 an srgilUoeout odour when beaUd. It dissolve* entirely in nitric acid 

 It U found in granite near Helsingfors in Finland. 



IU analysis by Nordanskiold gives 



Silica 43-93 



Alumina 28-93 



Oxide of Iron 5-30 



Magnesia -. . 290 



PoUah 1-05 



Soda 1-83 



WaUr 15-47 



99-41 



PYRKNEITR. [OAHUKT.] 



PYRKX K>TK.S. [FKlMiiLMDJK.1 



PYRKNOMYCETES. [Fvsci.] 



PYRETHRUM (from wvf, fire, because of the hot taste of the root), 

 a graus of Composite Placta belonging to the tribe Aita-acetr. It has a 

 bemuphi rical involucre, the receptacle flat or convex. The fruit angular 

 and not winged. The pappus an elevated membranous border. 



P. /'arfAratmH, Feverfew, has stalked pinnate leaves, with ovate or 

 oblong segments, and pinnatifid ; they are of a hoary green, the leaf- 

 let* incline to ovate decurrent and cut The flower-heads are erect, 

 about half an inch broad, with a convex yellow disc, and numerous 

 short broad abrupt 2-ribbed white ray*, often wanting, sometimes 

 multiplied, and the disc being obliterated constituting a double flower. 

 The whole plant is bitter and strong scented, reckoned tonic, stimu- 

 lating, and anti-hysteric. It was once a popular remedy in ague. It is 

 said that the odour is peculiarly disagreeable to bees, and that these 

 inaecU may be easily kept at a distance by carrying a handful of the 

 flower-heads. It is common in many parts of Europe and in England. 



f. itodcrum hat sessile pinnatifid leaves, in numerous capillary- 

 pointed segments. A branched stem, solitary brads, the involucml 

 scales lanceolate obtuse ; the fruit rugose with two round glandular 

 dots on the external face just below the elevated entire border. It is 

 found in fields and waste places in Great Britain. 



f. maril\m*m has sessile doubly pinnate leaves, with fleshy segment*, 

 convex above, keeled beneath. The stem diffuse and branched, the 

 heads solitary ; the fruit rugose, and with two elongated glandular 

 spot* on the external face, just below the elevated lobed border. It is 

 found on sea-shores in Great Britain. 



P. cfcmalt U the 1'ellitory of Spain, once much esteemed as a siala- 

 Rogne, and retorted to for relief in toothache. Grew says that " when 

 the root of Pyrethrum it chewed, it makes a sensible impression on 

 the lips, which continues like the flame of a coal betwixt in and out 

 for nine or ten minutes." When extracted, the acrid oil contained in 

 the root is said to be serviceable in cues of palsy, and when cutaneous 

 action is required, as a liniment Aiuslie aays it is administer d in 

 typhus fever by the Indian practitioners. 



(Lindley. Flora Mtdica; Babington, Manual of Britiih Botany.) 



PYRGITA. [PAWL] 



PYRGOH. [PTROXME.1 



I'YUUOMA. [ClBMPBDiA.] 

 1'VIilNA, a genus of Fos.il Echinodtrmata. 

 PYRITES. [COPTER ; lues.] 



PYROCHLORE, a Mineral which ocean in octahedral crystals. 

 Primary form a cube. Cleavage parallel to the face* of a regular 

 octobedron, but not easily to be obtained. Fracture conchoidal, with 

 a lustra between vitreous and resinous. Hardness 6-0. Colour red- 

 dish brown or black. Streak pale. Translucent, opaque. Specific 

 gravity 4-204 to 4 -216. Infusible by the blow-pipe ; become* greenish- 

 yellow by calcination. Found at Fradrichswiirn in Norway, and in 

 fcsTk. The analysis by Wuhler gives 



Titanic Acid ' 6275 



Lime 12-85 



Oxide of Cerium ..... 0'80 



Oxide of Uranium 6-18 



OxUle of Manganese 275 



Oxide of Iron 2'16 



i in. 1 of Tin 0-81 



Water 4-20 



98-8 



I'YROLA, a genus of Plants, the type of the order Pyrolacea. It 

 has the calyx 6-cleft, or 6 parted ; 6 petalt; 10 sUmena, slightly 

 adhering at Ui* base j style ustrUd ; stigma 6-lobed ; c*pule 6-cclled, 

 dehiscing D**r th* bate, and the margins of the valves connected by 

 tomeolum. 



P. nXiuidi/tiia, Round-Leavrd Winter-Green, has the stamens 



curved upwards ; the style declinate, arcuate at the apex ; the petals 

 obovate ; the segments of the calyx lanceolate-acute, recurved at the 

 apex, half the length of the corolla, and with equal racemes. This 

 plant is a native of Asia, Europe, and North America. It is found in 

 Great Britain, in the North of England, and the Highlands of Scot- 

 land, but it is a rare plant. It has milk-white flowers and numerous 

 leave*, and is the largest plant of the genus. There are four other 

 species of Pyrola natives of Great Britain ; one of these, P. unijtora, 

 is only found in Scotland. 



}'. aphylla. Leafless Winter-Green, hat no leaves, the scape it 

 angular, and furnished with numerous scales at the bate ; the raceme* 

 are many-flowered ; the petals are roundish, and the disc of the stigma 

 is elongated. This plant is a native of Nootka Island, on the north- 

 west coast of America, where it was collected by Mr. Menzies. It is 

 remarkable as indicating the approach of the genun to the character* 

 of JUonotropacea. It has globose pendulous milk-white flowers, and 

 the scales upon the scape are of a greenishoolour. 



Cliimajihila corymbota is the Pyrola umbfttala of Linntcus. [CuiM.v- 

 PHII.A.] 



PYItOLACK.K, Winter-Greetu, a natural order of Exogenous Plants. 

 It has the following characters : Calyx 5-leaved, persistent, inferior. 

 Corolla monopetalous hyppgyuous, regular, deciduous, 4- or 5-toothed, 

 with an imbricated aestivation. Stamens hypogynous, twice as numerous 

 as the divisions of the corolla; anthers 2-celled, opening by pores. 

 (I vary superior, 4- or 5-celled, many-seeded, with a hypogynous disc; 

 style 1, declinate; stigma slightly indusiate. Fruit capsular, 4- or 5- 

 celled, dehiscent, with central placenta;. Seeds indefinite, minute, 

 winged ; embryo minute, at the base of a fleshy albumen. (Liudlry.) 

 The species are herbaceous plants, rarely under-shrubs. The stem U 

 round, and in the frutescent species leafy. The leaves are simple, 

 and are either entire or toothed. The flowers are either solitary or 

 disposed in terminal racemes. Although often placed with Ericaceae, 

 the habit of these plants is very different from that order ; they have 

 also winged seeds, a minute embryo, and declinate styles, all marks of 

 difference which have induced Dr. Liudley to place them in an order 

 separate from Ericacea. Monotropaetcc are distinguished from this 

 order by their leafless scaly stems and parasitical habit. The embryo 

 also is at the apex of the albumen in Jfonotropactcr, while it is at its 

 base in Pyrolacea. Pyrola aphylla forms a passing link from Pi/rolacca 

 to it onotropaccce ; whilst Tolmiea, in the latter order, is a link in the 

 other direction. There is an approach to an indusiate stigma in 

 some of the species of Pyrolacea, which indicate an affinity with 

 d'oodeniacea. 



The following genera belong to this order : Pyrola, Chimaphila, 

 ilonaa, Cladolhamnui, Oalax. 



The species of these genera are natives of Europe, North America, 

 and the northern parts of Asia. 



Monttet and Cladoihanmiu have each one species. M. grandifulia 

 is a native of Europe, Asia, and North America, in alpine woods. C. 

 pyrolijloriu is a native of the north-west coast of America, and of the 

 island of Sitcha. 



Galax is a genus of doubtful position. 



PYROLUSITK [MANdANESK.] 



PYROMORPHITE. [LEAD.] 



PYROPE. [GABHET.T 



PYROPHYLUTE (Itadialtd Talc), a Mineral which occurs in 

 fibrous radiating masses and small prisms of indeterminate form. 

 Hardness 1*5. Colour light green. Lustre pearly, transparent in 

 thin lamina. Specific gravity 28. Before the blow-pipe it exfoliates 

 into white leaves, but does not fuse. With borax it give* a green 

 glass, which becomes colourless when cold ; with soda it gives a tran- 

 sparent yellow glass. It occurs near Beresof, in the Uralian Mountains, 

 Siberia. It* analysis by Hermann gives 



Silica 69-79 



Alumina 29-46 



Magnesia 4-00 



Oxide of Iron 1-80 



Water 5-62 



100-07 



PYRORTHITE, a Mineral, which occurs imbedded in granite or 

 quartz, in single or aggregated slender columnar masses. Fracture 

 conchoidal, uneven, earthy. Hardness 2-5. Colour blackish-brown. 

 Lustre resinous. Opaque, Specific gravity 2'19. When cautiously 

 heated by the blow-pipe it takes fire and burnt without either flame 

 or smoke ; it afterwards becomes white, and eventually fuses into a 

 block enamel. With borax it gives a transparent gloss. It dissolves 

 in acids when heated, except a black powder. It is found near 

 r'ahlun, in Sweden. The analysis by Berzelius gives 



Silica 1043 



Oxide of Cerium 13-92 



Oxide of Iron 6'08 



Yttria 4-87 



Alumina 3-S9 



Lime 1-81 



Oxide of Manganese 1-39 



Water 26-50 



Carbon and Loss 31-41 



100 



