PHO 



562 



PHO 



were brilliant like gold, and those of the 

 tail were purple and carnation down. 

 There could only be one such bird in the 

 world at a time. It lived 1000 years 

 according to some, and 500 according to 

 others ; after which it died, but sprung to 



life again from its own ashes. 2. The 



Date Palm-tree, a genus of nine species. 

 Diaecia Triandria. All the species are 

 natives of warm climates ; that which 

 affords the dates of commerce is the P. 



dacty ifera. 3. In astronomy, one of the 



southern constellations, so called after 

 the example of the Arabians, who wore 

 acquainted with it, under the appellation 

 of the Griffin or Eagle, from the most re- 

 mote antiquity. 



PHOLADA'RIA. A family of marine bivalve 

 shells, in the arrangement of Lamarck, of 

 > Inch the genus Pholas is the type. 



PHO'LAS. A genus of molluscs. Order 

 Acfphala testacea ; family Inclusa. The 

 shell is bivalvular, and convex towards 

 the mouth. Name pa/As> from QtaXiet , 

 a burrow, the pholades inhabiting 

 canals which they excavate, some in 

 ooze and others in stone, like the Litho- 

 domi, Petricolse, &c., and hence popularly 

 called stone-borers. They have a pecu- 

 liarly agreeable flavour. 



PHONET'IC WRITING, $vm, sound. That 

 writing in which the signs represent 

 sounds. 



PHON'ICS, from <poos, sound. The doc- 

 trine of sound ; otherwise called acoustics. 



PHON'OLITE, from povos, sound, and 

 X<flf, stone. Another name for clinkstone. 



PHONOL'OOY, from ^ovos, sound, and 

 Xoysj, discourse. The doctrine of the 

 sounds and tones of the human voice. 



PHOR'MIUM. Flax-lily, or New Zealand 

 FUx. A genus. Herandria Monogynia. 

 One species a perennial. New Zealand. 



PHOEONO'MIA, ) Gr. <pff, to carry, and 



PHORONO'MY. 



top* 



, a law. A term 



used to denote the science of motion, by 

 some of the older mathematicians; e.g. 

 Hermann's work entitled Phoronomia, 

 *H de Viribus et Motibus Corporum Soli- 

 donim et Liquidorum (Amster. 1716). 



PHORONO'MICS. The English word for 

 Phoronomia (q. v.). The term being less 

 expressive than the word mechanics, now 

 in general use to denote the science of 

 moving bodies, has been laid aside by 

 modern writers. 



PHOS'GENE, from fas, light, and ymetea, 

 to produce. Sec CHLOHO-CARBONIC ACID. 



PHOS'PHATES. Salts formed by the union 

 of the phosphoric acid with the salinable 

 bases. 



PHOS'PHITE. A salt formed by the com- 

 bination of the phosphorous acid with a 

 base. 



PHOSPHORESCENCE. The luminous ap- 



pearance presented by phosphorescent 

 bodies. The phosphorescence of sea- 

 water, occasionally observed, arises from 

 the presence of vast numbers of micro- 

 scopic medusae which float on its surface. 



PHOSPHOR'IC ACID. An acid formed by 

 the oxygenation of phosphorus. It exists 

 abundantly in the mineral, vegetable , and 

 animal kingdoms. In the mineral king- 

 dom we meet with phosphates of lead, 

 iron, copper, manganese, &c. In the ani- 

 mal kingdom the basis of all bone is 

 phosphate of lime, and this substance 

 forms a large portion of testaceous co- 

 verings. Phosphoric acid is always 

 formed when phosphorus is burned in at- 

 mospheric air or in oxygen. 



PHOS'PHOROUS ACID. When phosphorm 

 and corrosive sublimate acton each other, 

 at an elevated temperature, a liquid called 

 protochloride of phosphorus is formed. 

 Water added to this resolves it into mu- 

 riatic and phosphorous acids : a moderate 

 heat expels the former, and the latter 

 remains associated with water. 



PHOS'PHORUS, from <pwf> light, and 

 ?>l, to bear. A substance regarded as 

 elementary, having never yet been de- 

 composed. It is yellow and translucent ; 

 melts at 90 F., and boils at 550. In the 

 atmosphere, at common temperatures, it 

 emits white fumes, which in the daik 

 appear luminous: it is acidulous, and 

 results from the slow oxygenation of the 

 phosphorus. When heated in the air to 

 about 148, phosphorus inflames, and con- 

 tinues to burn, with much dense white 

 smoke, which is phosphoric acid. It is 

 obtained from bones by a chemical pro- 

 cess. 



PHOSPHOVIN'IC ACID. A crystallisable 

 acid, formed by the re-action of phos- 

 phoric acid and alcohoL Composition 

 Ph2 05 -t- C4 H6 O. 



PHOS'PHCRET. A compound formed by 

 phosphorus with a combustible or metallic 

 oxide. 



PHOS'PHDRETTED HYDROGEN. Hydro- 

 guret of phosphorus. A gas procured by 

 presenting phosphorus to nascent hydro- 

 gen, as by heating phosphorus in a solu- 

 tion of caustic potassa. It inflames spon- 

 taneously in atmospheric air, chlorine, 

 and nitrous oxide. 



PHOTOGEN'IC DRAWING. The name 

 given by the discoverer, Mr. H. F. Taibot, 

 to a process of making pictures by the 

 action of the light of the sun: whence 

 the name, from oj, light, and -yi^oua, 

 to produce. The process is this : a slip of 

 paper is brushed over with a solution of 

 nitrate of silver, and dried in the dark ; 

 it is then placed in a camera-obscura, 

 properly adjusted before the object (as a 

 building) whose image is to be taken. In 

 a few minutes, more or less (according t<j 





