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THE STANDARD DICTIONARY OF FACTS 



oil-cake is used for feeding cattle. The roots of 

 the poppy are annual or perennial; the calyx 

 is composed of two leaves, and the corolla of 

 four petals; the stamens are numerous, and the 

 capsule is one-celled, with several longitudinal 

 partitions, and contains a multitude of seeds. 



Porcupine. A name of certain rodent 

 quadrupeds, the best-known species of which 

 belong to the genus ////.x/n>. The body is cov- 

 ered, especially on the back, with the so-called 

 quills, or dense solid spine-like structures, inter- 

 mixed with bristles and stiff hairs. There are 

 two incisors and eight molar teeth in each jaw, 

 which continue to grow throughout life from 

 permanent pulps. The muzzle is generally 

 short and pointed, the ears short and rounded. 

 The anterior feet possess four, and the hinder 

 feet five toes, all provided with strong thick 

 nails. The common or crested porcupine, 

 hyxtrix rriattita, found in Southern Europe and 

 in Northern Africa, is the best-known species. 

 When fully grown it measures nearly two feet 

 in length, and some of its spines exceed one 

 foot. Its general color is a grizzled dusky black. 

 The spines in their usual position lie nearly flat, 

 with their points directed backwards; but when 

 the animal is excited they are capable of being 

 raised. The quills are loosely inserted in the 

 skin, and may, on being violently shaken, be- 

 come detached. 



Porgy. A fish of the family Sparidce, with 

 an oblong body, scaly cheeks, and one dorsal 

 fin, found off the coasts of the United States. 

 It is one of the most important food fishes, and 

 attains a length of eighteen inches and a weight 

 of four pounds. 



Porpoise. A species of marine fish-like 

 mammals, belonging to the same family as the 

 Dolphin, and to the order Cetacea. It is an in- 

 habitant of northern seas, and is familiar on 

 our own shores. It is usually from four to five 

 feet in length, though frequently more. In 

 color it varies, but is mostly of a bluish-black 

 tint on the upper surface, merging into pink, 

 mottled grey, or white beneath. The porpoise 

 is compelled continually to seek the surface of 

 the water for breathing purposes; and it is 

 then observed rolling over, as it were, and is 

 heard discharging air from the crescent-shaped 

 blowhole on the crown of the head, at the same 

 time taking in a fresh supply at the mouth. 

 Porpoises are frequently observed in great num- 

 bers in pursuit of shoals of herring, mackerel, 

 and other small fish, among which, being of an 

 exceedingly voracious nature, they commit sad 

 havoc. 



Prairie Dog. The name given to two 

 species of small rodent animals of the squirrel 

 family, found in America, on the plains east of 

 the Rocky Mountains from the Upper Missouri 

 to the Red River and Rio Grande. They much 

 resemble their allies, the marmots, in appear- 

 ance, and have well-developed claws on all the 

 toes of the fore-feet; shallow cheek-pouches; 

 and two rows of grinding teeth converging 

 towards the back of the mouth. The best 

 known species is about one foot in length, and 

 has a tail of about four inches. On the upper 

 surface it is reddish-brown variegated with 

 grey. These animals live together in great so- 



cieties on those portions of the prairies where 

 their favorite food, the buffalo grass, grows lux- 

 uriantly. Here they excavate burrows in the 

 ground in contiguity to each other, and, when 

 the little creatures are out, quite a busy scene 

 is presented. The name Prairie Dog is given to 

 the animal on account of a resemblance which 

 is supposed to exist between its cry and the hark 

 of a small dog. 



Precious Stones are those which, be- 

 cause of their beauty, hardness, and rarity, are 

 pri/ed for use in ornamentation, especially in 

 jewelry. The diamond, ruby, sapphire, and 

 emerald are the only stones which are, strictly 

 speaking, entitled to be called "precious" in 

 this sense; but the opal, on account of its beauty, 

 is often classed with the precious stones; as H 

 also the pearl, which is really not a stone, but a 

 secretion of a shell fish. 



Agate. A semipellucid, uncrystallized variety of 

 quartz, presenting various tints in the same specimen. 

 Its colors are delicately arranged in stripes or bam Is, or 

 blended in clouds. 



Alexandrite. A variety of chrysoberyl found in the 

 mica slate of the Ural Mountains. It is of a rich garnet 

 color by artificial light; by daylight of a dark moss 

 green. It is the only stone that so changes. The 

 finest specimens of alexandrite are nearly as valuable as 

 diamonds. 



Almandine. A common maroon-red variety of garnet. 



Amethyst. A variety of crystallized quartz, of a 

 purple or bluish violet color, of different shades. It 

 is much used as a jeweler's stone. The lighter colored 

 ones come from Brazil; the deep purple ones come from 

 Siberia. In value they are about the same as the garnet. 



Aquamarine. A transparent, sea-green variety of 

 beryl, used as a gem. 



Aventurine. A variety of translucent quartz spangled 

 throughout with scales of yellow mica. 



Beryl. A very hard mineral of much beauty when 

 transparent. It occurs in hexagonal prisms, commonly 

 of a green or bluish green color, but also yellow, pink, 

 and white. It is a silicate of aluminum and glurinum. 

 Beryls are very rich in colors. Their value is about four 

 dollars per caret. 



Cameo. A figure cut in stone or shell that is com- 

 posed of different colored layers. The value depends on 

 the artistic merit of the engraved figure. 



Bloodstone. A green siliceous stohe sprinkled with red 

 jasper, whence the name. 



Carbuncle. A beautiful gem of a deep red color 

 (with a mixture of scarlet), found in the East Indies. 

 When held up to the sun, it loses its deep tinge, and be- 

 comes of the color of a burning coal. The carbuncle of 

 the ancients is believed to have been a garnet. The 

 name is now given also to the ruby sapphire and the 

 red spinel. The ordinary carbuncle is a garnet cut en 

 cabochon, and is worth about one dollar a caret. 



Cornelian. A variety of chalcedony, of a clear, deep 

 red, flesh-red, or reddish white color. It is moderately 

 hard, capable of a good polish, and often used for seals. 

 It is now used but little. 



Cat's-eye. A variety of quartz or chalcedony exhibiting 

 opalescent reflections from within, like the eye of a cat. 

 The name is given to other gems affording like effects, 

 especially the chrysoberyl. A fine specimen about 

 three-eighths of an inch across would be worth from two 

 to three hundred dollars. 



Chalcedony. A crytocrystalline, translucent variety 

 of quartz, having usually a whitish color, and a luster 

 nearly like wax. 



Chrysolite. A mineral, composed of silica, magnesia, 

 and iron, of a yellow to green color. It is little used. 



Chrysoprase. An apple-green variety of chalcedony. 

 Its color is due to nickel contained in its composition. 



Dendrite. A stone or mineral in which are branching 

 figures, resembling shrubs or trees, produced by a 

 foreign mineral, usually by an oxide of manganese; as 

 in the moss agate. 



Diamond. A precious stone or gem excelling in bril- 

 liancy and beautiful play of prismatic colors, and remark- 

 able for extreme hardness. It is found in many hues 

 green, rose, straw, yellow, etc.; but the straw-colored 

 ones are the most common. The diamond is a native 

 carbon occurring in isometric crystals, often octahed- 

 rons, with rounded edges. It is the hardest substance 



