IGNATIUS OF LOYOLA. 453 IGNEOUS ROCKS. are treated of particularly in the book: the ser- vice of Jesus f'lirist. placed above all that the kings of the earth can offer ; the discernment of spirits; and finally the choice of a state of life. It was this book that accomplished the reforms the .Jesuits etfeeted. The Constitutions of the Jesuits are entirely the expressions of Ignatius's ideas. They have been but slightly modified, never in any essential, by successive Oeneral Conu:regations. Great writers have called them one of the world's works of genius. It is often said that Ignatius founded the .Jesuits to counteract the effects of the German Refonna- tion, but there is good authority for believinc; tliat when Ignatius conceived the idea of his Order he had not even heard the name of Luther. Kvcn more man a decade later, he seems to have paid little heed tn the religious movements in Europe, especially in Germany. One year before his death in 1555 the society comprised eight provinces, divided as follows: Italy, two; Spain, three ; Portugal, one ; Brazil, one ; India and Japan, one. In Germany there were but two residences — Cologne and Vienna. He died in Rome, .July 31, 1556. He was beatified in 1000 and canonized in 1622. Consult: Ribadeneira, Vita Ignatii Loiolw Hoc. Jesu Fvndatoris (Xaples, 1572; best re- cent edition, Barcelona. 1885), translated into most modern languages. For Ignatius's life as General of the Jesuits, his letters. Cartas de Snn Ignacio de Loyola (Madrid. 1874), are the authoritative sources of information. Ignatius dictated some autobiographical notes called the Acta, which must form the basis of an apprecia- tion of the man himself. There are several Eng- lish editions of this: Autobiography of St. Igna- tius (ed. O'Conor, S. J., New York, 1900), and Rix. The Testament of Ignatius Loyola (Saint Louis, 1900). Of recent lives the most authori- tative are: Clair, La vie de Saint Ignace de Loyola (Paris, 1891) ; in English, Stewart Rose (the Duchess of Buccleuch), St. Ignatius of Loyola and the Early .lesuits (New York, 1801) ; on excellent study of Ignatius the man, Joly, Snint Ignatius of Loyola (New York, 1890). in the Moniinicnta Ilistorirri Societatis Jesu (Ma- drid. 1804) there is a hitherto unissued life of Ignatius liy Polancn, who was a close personal friend. Consult, also. Hughes, Loyola and the Edurntinnril Si/stew of the .Jesuits (Great Edu- cators Series, New York, 1892). IGNATIUS'S BEAN, Saint. See Saint Ignatius's Bean. IGNEOUS ROCKS (Lat. igneus, fiery, from ignis, Skt. agni. fire). Rocks produced as the re- sult of solidification from a molten condition. Such rocks include lavas which have been poured out upon the earth's surface; the fillings of the fissures, pipes, and other passages in the earth's crust through which molten material was con- ducted during its rise to or toward the surface : and the larger masses which consolidated at great depths. The agents of decomposition and disintegration of rock material and those of transportation and degradation necessarily ex- pose to view these several types of igneous rocks, each of which possesses certain general and distin- guishing characteristics. The most noteworthy gener.al characteristic of the igneous rocks, when xinmetaniorphoscd, is a massive structure with- out lamination or bedding, such as is characteris- tic of the sedimentary or clastic rocks on the one hand ; or schistose structure, such as is developed in the metamorphic rocks. Inasmuch, however, as it has been shown that many metamorphic rocks (q.v.) have been formed from igneous rocks, it is clear that no sharp line can be drawn to separate the.se classes on the basis of structure, although in the main the above distinction ap- plies. Prominent among the textures characteristic of the igneous rocks are the granitic, the porphy- ritic. and the vitreous or glassy. The granitic texture is crystalline throughout and consists of an interlocking mosaic of the diflferent mineral constituents, the nearly uniform size of the grains indicating that the process of consolidation was essentially an uninterrupted one. and that prae- ticall.v the same conditions obtained during all stages of the process. In this mosaic the mineral constituents which first separated from the magma have more or less perfect crystal outlines, whereas those of later separation have irregular boundaries because sufficient space was not avail- able in which to build out their crystal faces. The porphyritic texture, which is the next most conunon among the igneous rocks, has crystals of one or more of the mineral constituents of the rock imbedded in a base or ground mass of smaller crystals, or of rock glass. The crystals imbedded in the ground mass are known as porphyritic crystals or phenocrysts. It is generally supposed that the phenocrysts were crystallized out of the magma in a stage of the process of consolida- tion earlier than that which produced the ground mass of the rock, and as most igneous rocks of porphyritic te.xture have been formed either at the surface of the earth or at quite moderate depths below it, it is supposed that the phenocrysts were formed at considerable depths before the magma rose to or near the surface. In the lavas that fiow from Vesuvius, or from most other vol- canoes, the phenocrysts may be picked out of the still molten lava as it flows from the volcano. The vitreous or glassy texture is one of com- paratively infrequent occurrence, but is repre- sented by obsidian (q.v.) and pitchstone. It is now generally recognized that many igneous rocks which have an entirely crystalline texture were once largel.y composed of rock glass, which has devitrified through processes of chemical altera- tion and crystallization. In addition to the above textures characteristic of igneous rocks and dependent upon the state of crystallization of the rock substance, there are numy others. One of the most common observed in lava (q.v.) is a peculiar crumpled lamination ot the rock caused by the arrangement of mineral constituents of unequal dimensions with their longer a.xes parallel to the crumpled lines of the texture. This fluxion te.xlure is conditioned by the fiow of the lava, the crumpled lines indicating the direction of flow. Other textures, as the amygdaloidal, scoriaceous, and pumiceous, which indicate different grades of cellular or porous texture, are conditioned by the steam once held in the lava and the opportunities for expansion and escape of this steam as the lava approached the surface of the earth. In chemical composition the igneous rocks show wide variation, though limits are set by the laws of formation of magmas. No such limits are ?e* for the clastic rocks. By processes of alteration the igneous rocks change into the metamorphic
