118 PYROXEXE are compounded of nitre 7 or 5 parts, sulphur 2, antimony 1 ; or for the sparkling ones, 4 each of sulphur and nitre, 1 of antimony, and 2 of fulminating composition (of fulminating mercury and gunpowder). The proportions of these ingredients may be variously modified from those given. The published works on pyrotechny are mostly of the 17th and 18th centuries. Those of more recent date are: L'art defaire d peu de frais lesfeux (Tartifice (Paris, 1828) ; Manuel 'de Vartificier, by A. D. Vergnaud (Paris, 1828); and *" Pyrotechny," by G. W. Mortimer (London, 1853). The full- est work in English is "System of Pyrotechny, comprehending the Theory and Practice, with the Application of Chemistry," by James Cut- bush (large 8vo, Philadelphia, 1825). PYKI)XKE (Gr. nvp, fire, and #vof, a stran- ger), a mineral species of Dana's augite section of the silicates, comprising numerous varie- ties. That to which the name was first applied, though found in the so-called igneous rocks, was supposed not to occur in modern lavas; whence the name. The species is interesting for its many varieties, which differ in physi- cal characters and chemical constituents, and consequently have been separated by differ- ent mineralogists among several species. They were first brought together under the head of pyroxene by Hatty, who recognized the iden- tity of the crystalline form common to them all ; and though for a time the relationship among them was not admitted by chemists, it was at last found that the differences in their composition resulted from the substitution of one isomorphous element for another, and that one general formula might be used to express the combination of silicic acid with one or more of the following bases (one replaced by another in any proportions), viz.: lime, mag- nesia, protoxide of iron, or manganese, and sometimes soda. Alumina may also enter into the composition, replacing it may be a portion of silicic acid, without essentially changing the crystallization. Among the varieties comprised in this species are the augites, coccolite, diop- side, sahlite, jeffersonite, and many others. PYROXYLIC SPIRIT (also known as pyrolig- neous spirit or ether, wood spirit or naphtha, methylic alcohol, hydrate of methyle, &c.), a spirituous liquid, not a product of fermenta- tion, but forming one of the most volatile con- stituents of pyroligneous acid, from which it is obtained in the process of purifying this acid by distillation; formula CH 4 O. (See ACETIC ACID, and NAPHTHA.) When purified, wood spirit is a colorless liquid of a penetrating em- pyreumatic odor, and a disagreeable burning taste. It is very inflammable, burning like al- cohol with a blue flame. It mixes with water, alcohol, and ether in all proportions. It boils at 150, and at 68 its specific gravity is 0'798 ; at 32, 0-8179. The substance was first recog- nized by P. Taylor in 1813; but its properties were first explained by Dumas and Peligot in 1835. In Great Britain wood naphtha, not PYRRHUS being subject to the excise duty, has been a valuable substitute for alcohol in various man- ufactures. By repeated rectifications over lime or chalk, and rejecting the latter portions in the distillations, it was obtained of strength varying from 80 to 90 per cent, of pure spirit, and of specific gravity from 0*87 to 0-83. From its property of dissolving the resins it was much used in the production of varnishes, lac- quers, &c., and by the hatters for their solu- tions of shellac. The medical properties of wood naphtha have not been fully investigated, but it has been regarded as narcotic, sedative, and anti-emetic. At present it is little used, if at all. Berthelot has prepared wood spirit ar- tificially by acting upon marsh gas with chlo- rine, and decomposing the chloride thus ob- tained by means of a solution of potash. PYROXYLINE. See EXPLOSIVES, vol. vii., p. 35. PYRRHA. See DEUCALION. PYRRUO, a Greek philosopher, a native of Elis, born about 360 B. C., died about 270. He was successively a painter, a poet, and a companion of Anaxarchus, under whose patron- age he joined the eastern expedition of Alex- ander the Great. He addressed a poem to that monarch, for which he received 10,000 pieces of gold. After the Indian campaign he returned to Elis, where he was made high priest, and for his sake a law was passed ex- empting philosophers from the payment of taxes. The only condition which he deemed worthy of a philosopher was that of suspended judgment. A man, he taught, should be in- different to all external circumstances of life, and allow nothing to disturb his equanimity. Virtuous imperturbability was the highest aim of life, but truth, from a scientific point of view, unattainable. Ho developed his views only orally, and his name was bestowed on all who shared them. The Pyrrhonists were called inquirers, skeptics, ephectics, and doubt- ers. His doctrines were expounded by Timon, Philo of Athens, Nausiphanes of Teos, and many others. PYRRHCS, son of Achilles. See NEOPTOLE- Mrs. PYRRHUS, king of Epirus, born about 318 B. C., killed at Argos in 272. He was the son of ^Eaoides and Plithia, and traced his descent from Pyrrhus, the son of Achilles, and was also connected with the royal family of Macedon. His father having been dethroned by the Epi- rotes, Pyrrhus was rescued and brought to Glaucias, king of the Taulantinns, an Illyrian people, who educated him with his own chil- dren. When Cassanders power in Greece waa weakened, his protector restored Pyrrhus to his throne; but he was again expelled by the Epirotes, and fled to his brother-in-law Demetrius Poliorcetes, who was then in Asia. He distinguished himself at the battle of Ipsus in 301, and subsequently went into Egypt ns a hostage for Demetrius. There he gained the good will of Ptolemy's wife Berenice, married
