POKISM. 258 PORPOISE. Aper^ historigue (3d ed., Taris, 1889) ; Gow, History of Greek J/u</ie»io(ics (Cambridge, 188-1). PORK (OF., Fr. pore, from Lat. porous, swine, hog, pig). The fle-sh of swine. This meat is •widely used and extensively exported for food and is valued for its heat-giving qualities and for the ease with which it may be preserved by salting, drying, or smoking. The pork-packing industry has grown to enormous proportions in the United States. In 1900. the bacon exported was valued at .$.39,000,000 ; the hams, $20,000,000 ; lard, $42,- 000,000; and the total hog products, over $112,- 000,000. The flavor of pork is affected more or less by the feed given to the pig, as is also the character of the fat. Fat with a low melting point is characteristic of 'soft' pork, while a higher melting point is found in that of better quality. Acorns are believed to cause the pecu- liar and delicate flavor noticed in the flesh of pigs which are allowed to run where they hav2 access to them. The over-fat carcass is now quite generally recognized as iindesirable, and smaller pigs with fat and lean well distributed are more satisfactory. Pork contains on an aver- age more fat than other meats, but does not dif- fer from them markedly in other respects as regards composition. It is often said that pork is unwholesome, but this seems to be wholly a matter of opinion, as so far as scientific food experiments go there is nothing to show that good pork is less desirable for men in health than other meats. It is very likely that much of the prejudice against pork comes from the fact that it is one of the foods avoided by the .lews and Mohammedans on account of their respective religious beliefs. See Packing Ixdustry; Meat; Food. POROMUSHIR, po'r6-moo-sher'. One of the Kurile group of islands. See Kubile Isla:sds. POROSITY ( from Lat. porosus, full of pores, from porii.s, pore, passage). A term expressing the experimental fact that no kind of matter com- pletely fills the space it occupies: in other words, that all bodies are full of minute cavities or interstices, such as are illustrated on a large scale by a sponge. PORPHYRIO, Posipo^at-s. A Latin gram- marian, presumably of the third century a.d. His commentary on Horace is the most valuable which has come down to us. though sometimes fanciful and frequently marred liy interpolations of mediteval clerks. It is edited bv Meyer (1874) and by Holder (1894). PORPHYRION (Lat., from Gk. nop0uplu»). In Greek mythology, a giant destroyed in the combat with the gods because at the sight of Juno's beauty he forgot to defend himself. PORPHYRITIC TEXTURE. See Igxeous EOCKS. PORPHYR'ITJS (Lat., from Gk. Xlopcpiptot, Porpluirios) ( 233-C..304 A.D.). One of the most im- portant Xeo-Platonists and the chief disciple of Plotinus. He was born at Batanea. in Syria, where he received his early education. His original name was Malchus. but this was changed, according to tradition, to Porphyrins ('wearer of the purple') by Longinus, whose disciple he was at Athens from 2.52 to 262. In the latter year he went to Rome and soon attached himself to Plotinus. After some years he moved to Sicily, but returned to Rome under Aurelian and con- tinued his teaching into the reign of Diocletian. Porphyrius was not a deep thinker. He devoted himself to grammar and history as well as phi- losophy, but his great service was as an expositor and dcfiner of Plotiuus's obscure doctrines, which Eunapius declares he made clear to the common imdcrstanding. He was a very prolific writer. Suidas has preserved to us an incomplete list of his writings, some of which deal with specu- lative philosophy, but the larger number were devoted to the history of philosophj- and its ex- position. The most important of these are his Life of Pythagoras, his work On Abstinence from Animal Food, an Introduction and Commentary to Aristotle's Categories, and a work addressed to his wife. Marcel la. Of his lost works the most important was one directed against the Chris- tians, which was publicly burned at the order of Theodosius II. That he was originally a Chris- tian, as is stated by Socrates, the Church his- torian, and by Saint Augustine, there is not the slightest proof. A complete edition of his works and fragments has never yet been pub- lished. The mo.st important editions of single works are the following: Porphyrii Opusciiln Helecta, by Xauck (2d ed., Leipzig, 188G) ; The Life of Pythagoras, together with lamblichus's similar work, by Kiassling (Leipzig, 1816) ; his Commentaries to Aristotle's Categories is now published m the great Berlin edition of the Com- mentaries to Aristotle, vol. iv., ed. by Busse (Ber- lin, 1887) ; Porphyrii de Philosophia ex Oraciilis Haurienda Lihrwum Reliquiw, ed. Gustav WollF (Berlin, 1856) ; Quwstiones Homericw, ed. Schra- der (Leipzig, 1880-82). Translation of Select Works, by Taylor (London, 1823) ; Sentences, by Davidson (ib., 1800). Consult: Zeller, Philo- sophic d-er Grieehen (3d ed., Leipzig, 1881) ; and for Porphyrius's I'elation to Christianity. Kleff- ner, Porpln/rius der Xcuplatoniker und Christen- feind (Paderborn, 1896). PORPHYRY (OF., Fr. porphyre. from Gk. Tr6p(pupos, porphyros, jiurple, from Trop<pupi. por- phyra, purjile fish). A term formerly much em- ployed to designate in a general way any rock of porphyritic texture ( see Igxeous Rocks ) , and in a special sense, such rocks when of siliceous composition and having the larger crystals (por- phyritic crystals) chiefly of orthoclase feldspar or orthoclase feldspar and quartz.. Thus quartz porphyry included the finer grained granites oc- curring as bosses or dikes. PORPOISE (OF. porpeis, porpois, pourpois, dialectic Fr. pourpeis, from Lat. porcus, swine, hog, pig -|- piseis, fish ; cf., with reversed order of components. Port, peixe porco, Olt. pesee porco, porpoise). A small active cetacean, of the fam- ; ily Delphinida', having a form similar to the dolphins, but the muzzle short, uniformly con- vex, and without a beak; a dorsal fin; the teeth numerous, simple, and equal. The common por- poise (Phoccemi communis) 'is plentiful in all northern seas and is only 6 to 8 feet in length. The body is sjiindle-shaped. the .skin perfectly smooth and destitute of hair, and there are from : 40 to 50 teeth in each jaw. The eye is rather | small, with the pupil in the form of a V, and the t opening of the ear i.s vers' minute. The crescent- shaped blow-hole is situated between the eyes. Large numbers are often seen together, sometimes gamboling, sometimes swimming in file, when their backs, appearing above the surface of the
