PYCNOGONIDE-PYM. will bear it. The internal administration of hyposulphite of soda and of the hyposulphites generally, has been lately recommended by Professor Polli of Milan. Considering that pyæmia is the cause of death in 10 per cent. of all cases of amputation, and in 43 per cent. of all fatal primary amputations, it becomes a question of great importance how it can be prevented. Persons whose health is already broken down require careful preparation before undergoing an operation. They must be strengthened,' says Mr Callender, by tonics, such as quinine and iron; and their secretions must be set right by appropriate alteratives; this treatment must be continued for a considerable period; for if the health be much broken, it is slow of taking effect, and its employment for only a few days prior to an operation is of course simply useless. The diet should at the same time be attended to; and persons of intemperate habits should be accustomed to a more healthy mode of living, although in no case should the stimulants be too suddenly withdrawn.' On the same principles, after the operation has been performed, these patients must have their strength supported by a nutritious diet; must have stimulants freely given them, if there are any signs of incipient prostration; and should take opium in sufficient doses to quiet the system and allay irritation. that every spring they were attacked by the cranes on the coasts of Oceanus. Later writers place them at the mouths of the Nile, but we also read of northern Pygmies inhabiting the region of Thule, and of Pygmies who lived in subterranean dwellings on the eastern side of the Ganges. Greek fancy worked hard to paint the Lilliputian dimensions of these creatures. It was said that they cut down every corn-ear with an axe; that when Hercules came into their country, they climbed up his goblet, by the help of ladders, to drink from it; and that, when he was asleep, two whole Pygmy armies fell upon his right, and another on his left, hand, but were all rolled up by the hero in his lion's skin. Aristotle did not believe that the stories about Pygmies were utterly fabulous, however much they had been overlaid by fancy with the marvellous. His 'rationalistic' (if not rational) interpretation was, that they were probably some diminutive tribe in Upper Egypt, who rode very small horses, and lived in caves. PYM, JOHN, famous as the leader of the popular party in the House of Commons in the reign of Charles I., was born in the year 1584. He came of a good family in Somersetshire, and was proprietor of the lands of Woolavington Pym and Woolavington Throckmorton, near Bridgewater, in that county. He was for some years a gentlemancommoner of Pembroke College, Oxford, and afterPYCNOGO'NIDÆ, a very remarkable family of wards studied law at one of the Inns of Court. Crustacea, of the section Edentata of Milne-Edwards, Having been sent to parliament as member for and forming the order Araneiformes (Spider-like) Tavistock, in Devonshire, he attached himself to of some authors. By Cuvier and many other the popular party; and, during the later part of naturalists, a place was assigned them among the reign of James I., became noted for his vigorous Arachnida; and it is only of late that they have opposition to the arbitrary measures of the court. been decidedly referred to Crustacea, in consequence In 1626, the year after the accession of Charles I., of the discovery that they undergo metamorphoses. he distinguished himself by taking a prominent part They are all marine, and some of them live among in the impeachment of the king's favourite, the algæ, or are to be found under stones on the beach, Duke of Buckingham. In 1640, the functions of whilst others are dredged from deep water. They parliament having been in abeyance for 13 years, seem to prey by suction on during which time the popular discontents had molluscs, but probably on gradually been growing to a head, the celebrated many kinds of marine Long Parliament was convened; and from the first, animals. The legs of many, P. was by common consent recognised in it as the as in the Русподопит, leader of the opposition to the despotic policy of the genus are furnished with hooks monarch. For the position which he thus occupied, for taking hold, and Linnæus his qualifications were eminent. In temper, he was believed P. littorale to be bold and fearless; he was master of an eloquence, parasitic on whales; but it close, terse, and vigorous; and in knowledge of is not uncommon among parliamentary form and business procedure, it was sea-weeds on the British considered he had scarcely his equal in the House. coasts. The suctorial pro- On November 3, as soon as business had opened, boscis of these creatures he set forth to the House, in a long and elaborate may be said to form the address, the intolerable grievances under which the whole head. The abdomen nation laboured; and a week after, he boldly deis almost rudimentary. Their most remarkable char-nounced the Earl of Strafford as the 'great promoter acteristic is in their digestive cavity. The stomach of tyranny,' to whose evil influence on the mind gives off from its circumference ten long cæca, four of the king these grievances were in the main to of which on each side extend into the proper or locomotive legs, the other two into the pincer-like rudimentary foot-jaws. These ramifications of the alimentary canal seem to serve all the purposes of the circulatory, respiratory, and chyliferous systems of higher animals. This arrangement, which appears also among the inferior tribes of some other classes of animals, has received from M. de Quatrefages the name of Phlebenterism (Gr. veinintestineism). The stomach of the P. with its cæca floats almost freely within the general cavity of the body in a fluid, which is kept in agitation by the Pycnogonum littorale. movements of the limbs. PY'CNOSTYLE. See INTERCOLUMNIATION. PY'GMIES (Gr. pygmē, a measure-from the elbow to the hand), a fabulous race of dwarfs in whose existence the ancients believed. Homer says be attributed. In the impeachment of Strafford which followed, resulting in his execution under a bill of attainder passed upon him, Pym took the leading part. Of this master-stroke of policy, which deprived the king of the one man of resolute temper and powerful genius who adhered to his cause, the credit must be chiefly awarded to Pym. In the subsequent proceedings against Laud, he was also conspicuous, as in every other crisis of moment, up to the time when war became inevitable between the king and the parliament. On the breaking out of hostilities, he remained at his post in London, and in the exercise of the functions of the executive there, rendered services to the cause not less valuable and essential than those of a general in the field. While the strife was yet pending, he died somewhat suddenly at Derby House, on December 8, 1643, having been appointed to the PYRACANTHA-PYRAMID. important post of Lieutenant of the Ordnance only the month previous. He was buried at Westminster Abbey with great pomp on the 13th; and in token of grief for the great parliamentary leader, was borne to his last resting-place by six members of the House of Commons. The House of Commons also voted £10,000 in payment of his debts. PYRACA'NTHA. See CRATÆGUS. PYRAMID, in Geometry, is a solid figure, of which the base is a plane rectilinear figure, and the sides are triangles, converging to a point at the top or apex.' Pyramids, like prisms, are named from the form of their bases; thus, a pyramid having a triangle for its base is a triangular pyramid, with a square base, a square pyramid, with any four-sided figure for its base, a quadrangular pyramid; or it may be pentagonal, hexagonal, &c. Pyramids may be either 'right' or 'oblique.' See PRISM. A right pyramid, with an equilateral figure for its base, has all its sloping edges equal; but this is not the case if the pyramid be oblique. The most remarkable property of the pyramid is, that its volume is exactly one-third of that of a prism having the same base and vertical height; and it follows from this, that all pyramids having the same base and height are equal to each other. A, PYRAMID, a structure of the shape of the geometric figure so called, erected in different parts of the Old and New World, the most important being the Pyramids of Egypt and Mexico. Those of Egypt were considered one of the seven wonders of the world, are seventy in number, of different sizes, are between 29° and 30° N. lat., and are masses of stone or brick, with square bases, and triangular sides. Although various opinions have prevailed as to their use, as that they were erected for astronomical purposes, for resisting the encroachment of the sand of the desert, for granaries, reservoirs, or sepulchres, the last-mentioned hypothesis has been proved to be correct in recent times by the excavations of the late General Howard Vyse, who is said to have expended nearly £10,000 in investigating their object and structure. They were all the tombs of monarchs of Egypt who flourished from the fourth to the twelfth dynasty, none having been constructed later than that time; the subsequent kings being buried at Abydos, Thebes, and other places, in tombs of a very different construction. The meaning of the word pyramid is involved in great obscurity; although attempts have been made to derive it from the Coptic piharam, yet, as in the hieroglyphs, it is found in connection with the words ben ben or ber ber, forms of the Coptic beebe mahou, or tomb, and abmer, or sepulchre, it is probably an ancient Greek word. The Pyramids are solid mounds raised over the sepulchral chambers of the kings, the first act of an Egyptian monarch being to prepare his future eternal abode.' For this purpose, a shaft of the size of the intended sarcophagus was first hollowed in the rock at a suitable incline to lower it, and at a convenient depth a rectangular chamber was excavated in the solid rock. Over this chamber, a cubical mass of masonry, of square blocks, was then placed, leaving the orifice of the shaft open. Additions continued to be made to this cubical mass both in height and breadth as long as the monarch lived, so that at his death all that remained to be done was to face or smooth the exterior of the stepformed mound. But in some cases, the masonry passed beyond the orifice of the shaft, which involved the construction of a new shaft, having its The orifice beyond it. The Pyramid was faced by adding courses of long blocks on each layer of the steps, and then cutting the whole to a flat or even surface, commencing from the summit. The outer masonry, however, or casing, as it is called, has in most instances been partially stripped off. Provision was made for protecting the vertical joints by placing each stone half way over another. means by which such immense masses of stone were masonry is admirably finished; and the mechanical raised to their places has long been a mystery; the discovery, however, of large circular holes in some of the stones has led to the conclusion that they were wound up by machines. The stones were quarried on the spot; sometimes, however, granite taken from the quarries of Syene was partially employed. The entrances were carefully filled up, and the passage protected by stone portcullises and other contrivances, to prevent ingress to the sepulchral chamber. There appears to have been also a door or pylon at the entrance of the shaft, ornamented sides of the pyramids face the cardinal points, and with Egyptian sculptures and hieroglyphs. the entrances face the north. The work of the larger Pyramids was executed by corvées of labourers. The most remarkable and finest Pyramids are those of Gizeh, situated on a level space of the Libyan chain at Memphis, on the west The Supposed Mode of Construction of Pyramids : (From Gliddon's Egyptian Archæology.) Section of a Pyramid; B, horizontal section of the base, rubble work, and casing of a Pyramid; C, apex of a Pyramid, shewing the process of finishing from the top downwards. bank of the Nile. The three largest are the most famous. The first or Great Pyramid, as appears from the excavations of Vyse, was the sepulchre of the Cheops of Herodotus, the Chembes, or Chemmis, of Diodorus, and the Suphis of Manetho and Eratosthenes. Its height was 480 feet 9 inches, and its base 764 feet square; in other words, it was higher than St Paul's Cathedral, on an area the size Its slope or angle was of Lincoln's Inn Fields. 51° 50'. It has been, however, much spoiled and stripped of its exterior blocks for the building of Cairo. The original sepulchral chamber, called the Subterranean Apartment, 46 feet x 27 feet, and 11 feet 6 inches high, has been hewn in the solid rock, and was reached by the original passage of 320 feet long, which descended to it by an entrance at the foot of the Pyramid. The excavations in this direction were subsequently abandoned, on account of the vast size attained by the Pyramid, which rendered it impracticable to carry on the entrance on a level with the natural rock, which had been cut down and 29 PYRAMID. faced for that purpose. Accordingly, a second chamber, with a triangular roof, was constructed in the masonry of the pyramid, 17 feet x 18 feet 9 inches, and 20 feet 3 inches high. This was reached by a passage rising at an inclination of 26° 18', terminating in a horizontal passage. It is called the Queen's Chamber, and occupies a position nearly in the centre of the Pyramid. The monument-probably owing to the long life attained by the monarch-still progressing, a third chamber, called the King's, was finally constructed, by prolonging the ascending passage of the Queen's Chamber for 150 feet further into the very centre of the Pyramid, and after a short horizontal passage, making a room 17 feet 1 inch x 34 feet 3 inches, and 19 feet 1 inch high. To diminish, however, the pressure of the superincumbent masonry on the flat roof, five small chambers were made vertically in succession above the roof, the last one pointed, varying in height from 1 foot 4 inches to 8 feet 7 inches, the apex of the top one being rather more than 69 feet above the roof of the King's Chamber. The end of the horizontal passage was finished in a superior style, and cased with red syenitic granite; and in the King's Chamber was the granite sarcophagus of the king Cheops, 7 feet 6 inches long, 3 feet 3 inches broad, and 3 feet 5 inches high, for whom the Pyramid was built.* As the heat of this chamber was stifling, owing to want of ventilation, two small air-channels, or chimneys, about nine inches square, were made, ascending to the north and south sides of the Pyramid. They perfectly ventilate this chamber. place in this Pyramid gave rise to various tradi tions, even in the days of Herodotus, Cheops being reported to lie buried in a chamber surrounded by the waters of the Nile. It took a long time for its construction-100,000 men being employed on it for thirty years, or more probably for above half a century, the duration of the reign of Cheops, which is dated by different chronologists at 3229, 3095, or 2123 B. C. The operations in this Pyramid by General Vyse gave rise to the discovery of marks scrawled in red ochre in a kind of cursive hieroglyphs on the blocks brought from the quarries of Tourah. These contained the name and titles of Khufu (the hieroglyphic form of Cheops); numerals and directions for the position of materials: with them were masonic marks. The second Pyramid is situated on a higher elevation than the first, and was built by Suphis II., or Kephren, who reigned 66 years, according to Manetho, and appears to have attained a great age. It has two sepulchral chambers, and appears to have been broken into by the Calif Alaziz Othman Ben-Yousouf, 1196 A. D. Subsequently, it was opened by Belzoni. The masonry is inferior to the first, but it was anciently cased below with red granite. The third Pyramid, built by Menkara, or Mycerinus, who reigned sixty-three years, is much smaller than the other two, being only 218 feet high by 354 feet 6 inches square. It has also two sepulchral chambers, both in the solid rock. The lower sepulchral chamber, which held a sarcophagus of Section of Great Pyramid of Gizeh : (From Vyse's Pyramids of Gizeh.) rectangular shape, of whinstone, had a pointed roof, cut like an arch inside; but the cedar coffin, in shape of a mummy, had been removed to the upper or large apartment, and its contents there rifled. Amongst the débris of the coffin and in the chambers were found the legs and part of the trunk of a body with linen wrapper, supposed by some to be that of the monarch, but by others to be that of an Arab, on account of the anchylosed right knee. This body and fragments of the coffin were removed to the British Museum; but the stone sarcophagus was unfortunately lost off Cartha D, débris and remains of casing; Q, queen's chamber; K, king's chamber; O, outer casing gena, by the sinking of line; S, N, air channels; W, well; sub., subterranean apartment. the vessel in which it After the mummy was deposited in the King's | to England. The masonry of this Pyramid is most was being transported Chamber, the entrance was closed with granite excellent, and it was anciently cased half-way up portcullises, and a well made at the junction of the with black granite. upward-inclined and horizontal passages, by which the workmen descended into the downward-inclined passage, after carefully closing the access to the sepulchral chambers. The changes which took *The opinion that this granite, or porphyry coffer, was a sarcophagus, has been questioned, and the theory has been advanced that it was a standard measure of capacity, of which the British quarter is the fourth part-See J. Taylor's The Great Pyramid; Why was it Built? (1859), and Piazzi Smyth's Our Inheritance in the Great Pyramid (1864). 30 and interest at Gizeh; one at Abou Rouash, five There are six other Pyramids of inferior size miles to the north-west of the same spot, is ruined, but of large dimensions; another at Zowyet El Arrian, also made of limestone, is still more ruined; another at Reegah, a spot in the vicinity of Abooseer, also much ruined, and built for the monarch User-en-Ra, by some supposed to be Busiris. There are five of these monuments at Abooseer, one with a name supposed to be that of a monarch of the third dynasty; and another PYRAMUS AND THISBE-PYRENEES. with that of the king Sahura. A group of eleven Pyramids remains at Sakkara, one with a doorway inlaid with porcelain tiles, and having a royal name. Five other Pyramids are at Dashour, the northernmost of which, built of brick, is supposed to be that of the king Asychis of Herodotus, and has a name of a king apparently about the twelfth dynasty. Others are at Meydoon and Illahoon; and two at Biahmo, at Medinat El Fyoum, apparently the sepulchres of the last kings of the twelfth dynasty. Some small brick Pyramids of the kings of the eleventh dynasty are at the Drah Aboo Negger at Thebes. In Nubia, the ancient Æthiopia, are several Pyramids, the tombs of the monarchs of Meroë, and of some of the Ethiopian conquerors of Egypt. They are taller in proportion to their base than the Egyptian Pyramids, and generally have a sepulchral hall, or propylon, with sculptures, which faces the east. The principal groups of these Pyramids are at Bege Rauie, or Begromi, 17° N. lat., in one of which, gold rings and other objects of late art, resembling that of the Ptolemaic period, were found. PY'RENEES, the name of that mountain-range which, separating France from Spain, extends 270 miles in length, and from 30 to 70 miles in breadth, from the Gulf of Rosas, in the Mediterranean, to the south-east corner of the Bay of Biscay. This mountain-system, covering an area estimated at 12,600 sq. m., consists of two great chains, one of which runs east from the Bidassoa to the west bank of the Noguera Pallaresa; and the other, originating in the Pic du Midi d'Ossau (9510 feet), lat. about 0° 25′ W., a little to the north of the former, extends eastward, and, after being intersected at the Val d'Aran by the Garonne and many smaller streams, reaches the Mediterranean, on the shores of which, immediately north of the Gulf of Rosas, it terminates in the promontories of Norfeo and Creuz. The northern slopes of these mountains to the plains and undulating districts of the south-west of France, are of gradual descent; while the southern slopes descend to the mountainous regions of Northern Spain by steep terraces. That portion of this mountain-system in which the eastern part of the southern, and the western part of the northern chains run parallel to each other, is called the High or Middle P.-a district about 16 miles in length, and forming the wildest and most elevated portion of the whole system. In the south-west of the Middle P. is a series of lofty summits, beginning with the Pic du Midi de Pau (9544 feet), and ending with_the_barren Maladetta, whose highest point, the Pic de Nethou or Malahite (11,168 feet), is the highest summit in the system. Between these two summits, there are several upwards of 10,000 feet In Assyria, the Birs Nimrud, or Tower of Belus, was a kind of step-shaped Pyramid of seven different-coloured bricks, dedicated to the planets by Nebuchadnezzar. The Mujellibe, another mound, was of pyramidal shape. The Pyramid also entered into the architecture of the tomb of Sardanapalus at Tanus, and of the Mausoleum of Artemisia at Halicarnassus. A small Pyramid, the sepulchre of C. Cestius, imitated from the Egyptian in the days of Augustus, still exists within the wall of Aurelian at Rome. Temples and other monuments of pyra-high, as Mont Perdu (10,994 feet). The northmidal shape are found in India, China, Java, the Polynesian Islands, and elsewhere. The Toltecs and Aztecs erected temples in Mexico, called Teocalli, or abodes of gods, of pyramidal shape, with steps or terraces by which to ascend and reach an altar, generally placed on the summit, where they performed human sacrifices and other rites. These, however, are not true Pyramids, the pure and simple form of which is restricted to Egypt. The Pyramid entered extensively into the architecture of the Egyptians, and appears on the tops of obelisks and tombs as a kind of roof. Small models of Pyra-line, as their highest summit, the Pic d'Anie, does mids, with inscribed adorations to the sun, or having royal names, were also placed in the tombs.-Lepsius, Ueber den Bau der Pyramiden, 1843; Briefe, pp. 143, 217; Wilkinson, Topogr. of Thebes (Lond. 1835); Vyse, Operations carried on at Gizeh in 1837 (8vo. Lond. 1840-1842); Gliddon, Otia Ægyptiaca (Lond. 1849). PY'RAMUS AND THI'SBE. The tragical history of these two lovers is told by Ovid in the 4th book of his Metamorphoses. They were natives of Babylon, and tenderly attached to each other, but as their parents would not hear of their marriage, they had to content themselves with clandestine interviews by night. On one occasion they arranged to meet at the tomb of Ninus, where Thisbe, who was first at the trysting-spot, was startled to discover a lioness. She immediately ran off, but in her terror and haste, dropped her garment, which the fierce animal, that had just torn an ox in pieces, covered with blood. Soon after, Pyramus appeared, and seeing his mistress's robe, came to the conclusion that she had been murdered, whereupon he killed himself. Thisbe now returned, and beholding her lover lying dead on the ground, put an end to her own life. The story was a favourite one during the middle ages, when a couple, unhappy in their love, were termed a Pyramus and Thisbe. Shakspeare, in his Midsummer Night's Dream, has introduced it but in a way that has the effect of caricature. eastern and less elevated portion of the Middle P. not rise above 7500 feet. Forming at first ridges PYRÉNÉES-PYRITES. with lofty forests, and beautiful mountain pasture. Granite forms the kernel of the Pyrenean mountain-system, and is overlaid by chalk and sandstone masses. The P. are not rich in metals, but abound in mineral springs, of which the chief are those of Bagnères de Bigorre (q. v.) and Barèges. The PYRÉNÉES, BASSES, a department forming the south-west corner of France. Area 2943 sq. m.; pop. 436,628. The department is divided into the five arrondissements of Pau, Oloron, Orthez, Bayonne, and Mauléon. Chief town Pau. Basses-P. occupies the northern slopes of the Western Pyrenees, offshoots from which divide the department into a number of valleys, each traversed by a clear mountain stream, locally known as a gave. The chief of these are the Gave d'Oloron, Gave de Pau, the Bidouze, and Nivelle. The high valleys and slopes are generally fertile, and well adapted for the growth of the vine, chestnut, various other fruits, and maize, though not for wheat. The best wines are those of Jurançon and Gau, Pontac and Auberlin. Flax and hemp, rye, barley, oats, and millet are also grown; but the principal source of industry, after the making of wine, is the rearing of horses, cattle, sheep, and mules for the Spanish markets, and the raising of swine in the great beech-forests, together with the preparation of hams of excellent quality and high flavour. Marble, alabaster, slate, ophite, copper, iron, sulphur, and cobalt, constitute the chief mineral products; but their importance as sources of wealth falls short of that of the numerous mineral springs, the most important of which are those of Biarritz, Cambo, Eaux-Bonnes and Eaux-Chaudes. PYRÉNÉES, HAUTES, a department of France, lying east of the Basses-Pyrenees, is a part of the old province of Gascony. The Hautes-P., which, as its name implies, contains the loftiest summits of the Pyrenean chain, is divided into the three arrondissements of Tarbes, Argèles, and Bagnères, and the chief town is Tarbes. The aspect of the scenery is, moreover, very varied-savage mountains and precipitous rocks in the south, an agreeable diversification of hill with dale in the centre, softening down to fertile plains in the north. The principal rivers, none of which, however, are navigable in the department, are the Adour and the Gave de Pau. The climate is generally mild in the plains and sheltered valleys, but even there, storms are of frequent occurrence. The well-cultivated and artificially watered low lands yield good crops of cereals, leguminous plants, flax, fruits of every kind, including the grape, from which excellent wine and brandy are made. Horses, mules, cattle, sheep, swine, and poultry, are much reared. This department, which is the richest part of the Pyrenees in mineral products, especially marble of various kinds, copper, iron, zinc, lead, antimony, slate, granite, &c., contains also the most celebrated springs, as the sulphur springs at St Sauveur, and the hot-baths of Bagnères, Barèges, and Cauterets. The very limited commercial industry of Hautes-P. embraces the manufacture of woollen and mixed fabrics, including bareges, colouring matters, leather, paper, cutlery, &c. There is also an active smuggling trade with Spain. PYRÉNÉES-ORIENTALES, a maritime department of France, is bounded on the E. by the Mediterranean, and on the S. by the Pyrenees. Area 1592 sq. m.; pop. (1862) 181,763. It is divided into the three arrondissements of Perpignan, Prades, and Ceret. The chief town is Perpignan. Like the two previously described, this department presents a series of parallel valleys formed by spurs from the Pyrenees, but in this case the valleys run east and west. They are three in number, and are watered by the Gly, Tet (the principal river), and Techs. The south-west corner is drained by the Segre (Segura), a tributary of the Ebro. An extended plain occupies all the north and east of the department. The climate is good, and in the plains is seldom disturbed by great extremes of heat or cold. The vegetable products include fine grain and some of the choicest fruits of this latitude. Wines constitute the wealth of the district, and include the red wines of Roussillon, the white muscatel of The chief Rivesaltes, and other approved kinds. exports are wine, cocoons, the surplus live stock and its products, sardines, anchovies, &c. mineral wealth of the district is not remarkable. The PYRITES, a name employed by mineralogists to designate a large group or family of minerals, compounds of metals with sulphur, or with arsenic, or with both. They are crystalline, hard, generally brittle, and generally yellow. The name P. originally belonged to the sulphuret of iron, known as IRON P.; and was given to it in consequence of its striking fire with steel (Gr. pyr, fire), so that it was used for kindling powder in the pans of muskets before gun-flints were introduced. Iron P. is commonly of a bright brass-yellow colour; it is often found crystallised in cubes, in which form small crystals of it are abundantly disseminated in some roofing-slates; and very large ones occur in some of the mines of Cornwall; it is also found crystallised in dodecahedrons and other forms, more rarely in oblique four-sided prisms; and it often occurs massive, globular, stalactitic, capillary, or investing other minerals as an incrustation. Beautiful speci England. It is a very widely diffused and plentiful mens of globular iron P. are found in the chalk of mineral, and seems to belong almost equally to all geological formations. It is too abundant in many coal-fields, the action of water and air changing it into sulphate of iron (vitriol), during which change kindled by it, mines become unworkable, and the so much heat is evolved that the coal is frequently by building up portions of them to cut off the of the fire can only be stopped, if at all, progress access of air, or by the admission of a plentiful supply of water. At Quarreltown, in Renfrewshire, century ago, the ground fell in, in consequence of a a deep hollow may still be seen, where, about a subterranean fire thus kindled. The colour of Iron P. has often caused it to be mistaken for gold, a mistake which its hardness and comparative lightness should prevent, or its ready solubility in nitric acid, and its burning before the blowpipe on charcoal with bluish flame and smell of sulphur. But it sometimes does contain a small proportion of gold, sometimes even in visible grains. This auriferous Iron P. is found in Siberia and in South America. Iron P. is never used as an ore of iron, but it is much used for the manufacture of sulphuric acid, and sulphur is obtained from it by sublimation. It is also used for the manufacture of alum. A variety of Iron P. of a very pale colour is called Marcasite. There is also a magnetic variety. COPPER P., also called Yellow Copper and Chalcopyrite, is the most abundant of all the ores of copper, and yields a large proportion (perhaps a third) of the copper used in the world. It is brass-yellow, the colour varying with the amount of copper which it contains, a rich colour indicating much copper, and a pale colour the presence of a comparatively large amount of iron; for this ore is not a sulphuret of copper, but of copper and iron. It occurs massive and disseminated in rocks of almost every class; and is often found crystallised in octahedrons and tetrahedrons, but generally in very small crystals. It may at once be distinguished from Iron P. by its |