PORDENONE 



6261 



PORPHYRIUS 



venturing among the grass. Horses 

 and dogs are. badly lamed by it, 

 and wallabies and kangaroos avoid 

 ground covered by it 



Pordenone, IL. Name taken by 

 the Italian painter, Giovanni An- 

 tonio Licinio (1483-1539). Born 

 near Pordenone, Venetia, he 

 studied under Pellegrino da San 

 Daniele at Udine, but he was at 

 Mantua in 1520, at Venice in 1528, 

 and at Piacenza in 1529, settling at 

 Venice in 1536, where he proved a 

 rival to Titian. His frescoes in 

 Treviso Cathedral and the altar- 

 piece of The Trinity for the 

 cathedral of San Daniel are note- 

 worthy. See Licinio, G. A. 



Porifera. Sub-kingdom or phy- 

 lum of animal life consisting of the 

 various forms of sponges. In this 

 phylum we first meet with simple 

 cellular organisms, such as consti- 

 tute the Protozoa, being aggre- 

 gated to form tissues. See Sponge. 



Porism (Gr. porizein, to bring 

 about, deduce as a corollary). In 

 ancient mathematics, one of the 

 divisions into which propositions in 

 geometry were divided, the other 

 two being theorems and problems. 

 In a porism it was required to find 

 something, e.g. the centre of a 

 given circle ; a problem required 

 something to be done, e.g. the con- 

 struction of a circle in a given tri- 

 angle ; while a theorem was some- 

 thing to be demonstrated, e.g. the 

 tangents from any point to a circle 

 are equal. 



Pork (Lat. parcus, hog). Un- 

 cured flesh of the hog. In Great 

 Britain by far the greater part of 

 the consumption of the flesh of the 

 pig is in the form of bacon. Still 

 there is a considerable demand for 

 fresh and salted pork, which is 



met to a large extent from home 

 supplies, and partly from Holland 

 and Belgium, and to some extent 

 from America. This demand was in- 

 creased in the year before the Great 

 War by the admission of pork into 

 the diet of the army and navy. In 

 the United States, and in Canada, 

 pork is a standard and favourite 

 article of diet. Pork and beans is 

 a staple food. 



The United States is the greatest 

 hog-producing country in the world, 

 and the demand of the Allies for 

 food during the Great War led to an 

 enormous increase in the numbers, 

 which rose from 61 million in 

 Jan., 1913, to 75 million in 1919. 

 This increase was fostered by the 

 American Food Administration, as 

 a pig can be brought, under good 

 management, to the slaughter 

 stage in a little over six months, 

 and pig-keeping is regarded as the 

 most economical way of using 

 surplus grain. The greater part 

 of American production is absorbed 

 in the States, but the exportable 

 surplus was raised to 20 p.c. during 

 the war. The greater part of the 

 export of the hog slaughter-houses 

 of Chicago to England was, how- 

 ever, in the shape, not of pork, 

 but of bacon. Attempts were made 

 before the war to encourage the 

 export of salted pork from China. 



Pork is a forbidden food both 

 to the Mahomedan and the Jew, 

 perhaps originally because it de- 

 teriorates rapidly in hot weather, 

 and is therefore unsuited for use 

 in the climate of the Mediterranean 

 countries. Hutchison (Food and 

 Principles of Dietetics) states that 

 the comparative indigestibility of 

 pork is shown by the fact that 

 3J- oz. required 3 hours for their 



Porcupine. 1. Brush-tailed African variety, Atherura africana. 2. Crested, 

 and, 3, Long-tailed porcupines, European varieties. 4. Brazilian tree porcu- 

 pine, Synetheres prehensilis 



W. 8. Btrridgc, F.l.S. 



digestion, as compared with 2 hours 

 for beef. The difficulty is said to 

 be due to the large accumulation of 

 fat between the fibres. The fat of 

 bacon, on the other hand, is diges- 

 tible because of its granular com- 

 position. Medium fat pork con- 

 tains 60'9 p.c. of water, 12'3 p.c. 

 protein and gelatin, 26'2 p.c. fat, 

 and 0"6 p.c. ash. In very fat pork 

 the percentage of protein and 

 gelatin may be as low as 9'7 p.c., 

 and the fat content as high as 

 45'5 p.c. 



Porlock. Village of Somerset, 

 England. It is 6 m. from Minehead, 

 on the edge of Exmoor, about a 

 mile from the coast. The church of 

 S. Dubritius is an old building re- 

 stored. Near are West Porlock and 

 Porlock Weir. Porlock Bay is an 

 opening of the Bristol Channel, 

 about 4J m. across. Before the sea 

 receded, Porlock was a flourishing 

 seaport and a market town. Pop. 700. 



Porosity. Term used to express 

 the fact that no matter completely 

 fills the space it occupies. This is 

 hypothetically true on the hypo- 

 thesis that matter consists of atoms 

 which necessarily have spaces in 

 between them, and is practically 

 shown by the fact that all matter is 

 compressible. Some substances are 

 obviously porous, e.g. earthenware, 

 pumice stone, blotting-paper, etc., 

 while others, as water, metals, etc., 

 have very fine pores and conse- 

 quently are not easily compressed. 



Porphyrites. In geology, name 

 given to certain types of igneous 

 rocks. They are intrusive rocks of 

 porphyritic texture, occurring as 

 dikes and sills, and their felspar is 

 plagioclase. Rocks of this class are 

 usually grey in colour with pheno- 

 crysts of plagioclase felspar, horn- 

 blende, biotite, or augite, and are 

 found in Scotland, Wales, N. 

 America, the Swiss Alps, etc. 



Porphyritic Structure. In 



geology, name given to a particular 

 rock formation. It is characterised 

 by the occurrence of two distinct 

 series of crystals. One series forms 

 a ground mass of extremely fine 

 crystals, in which the other series of 

 large well-formed crystals is em- 

 bedded. These latter crystals are 

 called phenocrysts. Eocks of this 

 class often make beautiful orna- 

 mental stones. 



Porphyrius OK PORPHYRY (A.D. 

 233-304). Neo-Platonist whose 

 real name was Malchus (king). 

 Born at Batanea in Syria, he spent 

 most of his life in Rome, where he 

 /was a pupil of Plotinus, whose 

 literary remains he edited with a 

 biography. In one of his works he 

 discusses the problem of the nature 

 of universals, much debated during 

 the Middle Ages. He died at Rome. 

 He was a bitter anti-Christian. 



