Page:The American Cyclopædia (1879) Volume XI.djvu/509

 MICAH MICHAEL ANGELO 491 the biotites below 5. Prof. B. Silliman, jr., observes that the rnuscovites are confined to granitic and other igneous rocks, and the phlo- gopites to granular limestone and serpentine. The former generally contain potash or lithia and little magnesia, and the latter contain mag- nesia, and often but little alkali. The compo- sition of the most common micas, according to Dufrenoy, is from 45 to 50 per cent, of silica, 32 to 38 of alumina, 10 to 15 of alkali (rarely soda), and 2 to 4 of fluoric acid. He considers the differences of composition too great to admit of any general formula. The micas are unisilicates, containing, besides silica and fluo- rine, alumina, iron, magnesia, potash, lithia, rubidia, and csesia, the magnesia generally fail- ing in the varieties found in the granitic rocks. Lepidolite is a species distinguished for its oc- currence usually in granular masses made up of foliated scales of rose-red color, violet gray, yellowish, or whitish. Muscovite, the most familiar form of mica, is a constituent of gran- ite, gneiss, mica slate, and some other kindred rocks. It is found both disseminated and in veins, and in many of the stratified rocks it is an incidental constituent derived from the de- struction, of the original formations to which it belonged. The mineral is thus seen to be very generally distributed ; but certain locali- ties are distinguished for the production of large plates of it. In Siberia they have been found more than 3 ft. across, and they have been obtained of great size in Sweden and Norway. This is also the case at Ac worth, Grafton, and Alstead, N. H. ; and mica has been found in some of the other states and in Canada sufficiently large to be quarried for economical purposes. Mica is used mostly for the doors of stoves and the sides of lanterns, for which it is well adapted by its transparency and refractory character. It has been used as a substitute for window glass, and its tough- ness recommends it for this purpose on board vessels of war, in which the concussion from the discharge of heavy guns might occasion the fracturing of glass. It has also been used for spectacles, optical instruments, and bronz- ing powder, and is serviceable for holding small objects for microscopic examination. Very extensive mica mines were discovered in Mitchell co., N. C., in 1867, which have since been extensively worked. They had evidently been worked centuries ago. MICAH, one of the 12 minor prophets, who, according to the testimony of his book (i. 1), prophesied in the days of Jotham, Ahaz, and Hezekiah, kings of Judah (about 759-698 B. C.). He was a native of Moresheth of Gath. The prophecy of Micah consists of two parts, the first of which terminates with chapter v. It begins with a sublime theophany, the descent of the Lord to judge the nations of the earth, and then denounces the iniquities of the two Hebrew kingdoms, especially of the rulers and prophets, predicts the captivity of Israel, the fall of Judah, the destruction of Jerusalem, the expatriation* of the Jews, their return, and the celebrity of the temple of Zion. Bloody wars are seen in the perspective, and after many calamities a ruler is seen to come forth from Bethlehem (v.). The second part consists of a discussion or controversy between the Lord and his people. The authenticity of the book is generally recognized ; only the last two chap- ters have been ascribed by Ewald to a young- er prophet. The style of Micah is sublime and vehement. Among the principal critical writings on Micah are those of Caspari, Micha der MorascMte und seine propJietiscJie ScJirift (Christiania, 1851) ; Hitzig, Kleine Propheten (3d ed., 1863) ; and Ewald, Propheten (vol. i., 1867). Micah, or Micaiah, was also the name of another prophet mentioned in the history of Ahab, king of Israel (1 Kings xxii. 8-28). MICALI, Giuseppe, an Italian archaeologist, born in Leghorn about 1776, died in Florence, March 28, 1844. He travelled extensively, and devoted himself to archaeological- studies. His Italia avanti il dominio de" 1 Eomani (4 vols., Florence, 1810, with a map and 67 plates; new ed., 1831), won a prize, but incurred criticism, which induced the author to remodel it under the title Storia degli antiehi popoli italiani (3 vols., 1832 ; 2d ed., Milan, 1836 ; enlarged ed., 4 vols., Florence, 1843 et seq. ; translated into French by Raoul Rochette). It was fol- lowed by Monumenti antichi, a volume con- taining 120 plates (Florence, 1844). MICA SLATE, a very abundant metamorphic rock, consisting of mica and quartz, and some- times feldspar, in which the mica predomi- nates, and by its arrangement in parallel planes gives to the aggregate a foliated structure. It belongs to the mica-bearing series, of. which granite and gneiss are also members. Some authors classify it under the same head with mica schist, while others, place it midway be- tween mica schist and clay slate. What is called mica schist sometimes contains numer- ous garnets imbedded in it, when it receives the name of garnet schist. It is prevalent along the banks of the Tay and about Dunkeld in Scotland, and also in the Blue Ridge moun- tains in the United States. MICHAEL (Heb., who is as God), the angel who had special charge of the Israelites as a nation (Dan. x. 13, 21), who disputed with Satan about the body of Moses (Jude 9), and who with his angels carried on war with Sa- tan and his angels in the upper regions (Rev. xii. 7-9). The Jews regarded Michael as one of the archangels, and the Christian church early adopted this view. The representation of Michael, sword in hand, conquering the dragon, became a favorite symbol in the Ro- man Catholic church. A festival of St. Michael was introduced by Pope Felix III. (483-'92), and it was retained also in the Lutheran church. Mohammedans regard Michael like- wise as one of the archangels, and as guar- dian angel of the Jews. MICHAEL MGELO. See BTJONAROTTI.