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ARTS, SCIENCES, HISTORY,
THOUSANDS OF ENGRAVINGS, COLORED MAPS AND CHARTS
PREPARED UNDER THE SUPERVISION OF
JOHN CLARK RIDPATH, LL.D.
ASSISTED BY A LARGE CORPS OF EDITORS AND OVER ONE HUNDRED WRITERS
ON SPECIAL SUBJECTS
156 FIFTH AVENUE, NEW YORK
4.5 5.0 3.5 1.5
7.5 7.0 7.0 5.5
9.0 8.0 5.5 4.5
62.5 50.0 44.0 38.0
Porcelain. See POTTERY.
of the body, chiefly as perspiration. There are about 7,000,000 Por'celain, Japanese. The exhibit of rare porcelain at Ps. in an ordinary sized man. Each P. is about 1 in. in l.; the Centennial Exposition, 1876, brought to light many in- 8,528 Ps. have been counted on 1 sq. in. of the palm of the teresting facts concerning the native mineral materials hand. There are 175,000 in. of Ps.-i. e., 145,833 ft., 48,600 from which J. P. goods are made, and their skill in the yds., nearly 28 m. of this drainage in a human body. manufacture. Only one of the Idzumi-Tama minerals ex- Por'gy, an Amer. fish, common to New York and its viamined bears the least resemblance to clay. The peculiar cinity, as well as to other points of the Amer, coast, family Japanese kilns are always built on the slope of a hill, 4 to Sparrido. It is a very abundant, cheap fish, and is much 20 in a set. Ideas of higher ceramic art were imported into prized for its savory flesh. Japan from China and Corea about 300 yrs. ago. Gorodayu Porif'era, or Sponges, many-celled animals with tissues Shonshi first made porcelain 1580. The “Satsuma" ware arranged in three layers, without a true digestive cavity; the was originated by Corean prisoners about 1592.
soft parts supported usually by calcareous or siliceous spicules. Porch, a building forming an inclosure or protection for a The body-mass is permeated by microscopic ciliated passages doorway. Every one knows how
opening into minute chambers lined by ciliated monad-like much this beautiful feature is
cells. There is no truc mouth-opening, but usually an irregular now used, and how efficient it is
system of inhalent pores opening into the digestive cell-lined as a protection from the wind
will chambers or passages through which the food is introduced in and weather. In Elizabethan
currents of sea-water. Sponges grow from eggs. Of the mar. and mediæval architecture the
ketable sponges there are six species, with numerous varieties, P. was also very common
They are available for use in bathing from being simply in domestic architecture. In
fibrous, having no hard, siliceous spicules. The Mediterranean churches it was almost universal
sponges are the best, while our West Indian kinds are coarser in England. In France many
and less durable. splendid Ps. or portals remain,
Poʻrism, a kind of geometric proposition in high favor and they are among the most
among ancient Greek mathematicians, but of which the beautiful specimens of mediæ
notices that have come down to us are so few and meager that val art. In England wooden
till lately mathematicians were not agreed about what a P. Ps. of picturesque structure,
really was. As defined by Playfair, “a P. is a proposition afare very common in ancient parish churches.
firming the possibility of finding such conditions as will render Por'cher, (Francis PEYRE, M.D.,) a distinguished physi- a certain problem indeterminate, or capable of innumerable cian of S. C., editor of several medical books and reviews; solutions." Prof. of Materia Medica and Clinical Medicine in South Pork, the flesh of swine, forms a very large portion of the Carolina State Medical Coll.; b. 1824.
animal food of most nations, although it is not the most nuPorcu'na, an ancient and picturesque Span, town, in the tritive, as will be seen by the following comparison of the four prov. of Jaen; pop. 7,645.
principal kinds of flesh-food : Porcu'pine, a genus of mammalia, of the order Rodentia,
Mineral and family Hystricidæ. This family is remarkably character
Fibrine and ized by an armature of spines, which, like those of the hedgehoys, are, as to their structure, merely thick and strong hairs. Yeal.
Beef The Hystricidæ are plantigrade ; the fore feet have four toes
Mutton. and a rudimentary thumb, the hind feet have five toes. Their Pork. general aspect is heavy and pig-like, and they have a grunting voice. The muzzle is broad and blunt; the ears short It has qualities, however, which especially fit it for man's use ; and rounded; the incisors smooth and large, two above and its fatness makes it a very heat-giving food for cold and temtwo below; the molars eight above and eight below. The perate climates, while it surpasses all other kinds of animal
food in the ease with which it may be preserved by salting and drying. Hence the trade in P. is considerable in all countries where it is used, but especially so in Am. and Great Brit. ain, particularly the former country, where vast quantities are cured for the supply of ships, for home use, and for exportation.
Poros'ity. By this term we ex. press the experimental fact that no kind of matter completely 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. On the atomic theory, it is obvious that this must be the case if the atoms of matter are spherical, or, indeed, if they have any form save one or two special ones, such as cubes or rhombic dodecahedrons. It is commonly asserted
that all bodies must be porous, be. numero
cause they are compressible; but this Porcupine.
is a great mistake, since we have no
reason to believe that matter is not name P. is derived from the Lat. porcus," swine," and spina, per se compressible, independently of the existence of inter"a thorn." The Common P. is a native of the S. of Eustices. rope, of many parts of Asia, and of the most parts of Africa. Porphyr'ius, one of that series of ancient philosophers to The spines or quills of the P. are used for various purposes, whom is due the reformation of the Greek philosophy known and have a certain commercial value. It is chiefly sought on as Neoplatonism, was probably b. at Batanea, in Syria, in the account of them, although its flesh is eaten, and was brought yr. 233 A.D. His original name was Malchus, the Greek form to the market of ancient Rome.
of the Syro-Phænician Melech, or king. The name by which Pordeno'ne, a town of Venetia, Italy, in the prov. of he is known in history is P. "He is said by Socrates the his. Udine. The site is supposed to be that of the Portus Naonis torian, and by St. Augustine, to have been originally a Chris. of the Romans. Pop. 8,269.
tian. It was at Rome, however, whither he repaired soon after Pore, an opening or narrow passage in any solid substance, 260, that he entered upon what must be regarded as, histormore especially in the glands and skins of animals. They ically considered, the career of his life. Here he became a serve the purpose of throwing off the waste or effete portions scholar of the Neoplatonist Plotinus. After six yrs.' residence