COSMAS. 456 COSMOGONY. COSMAS (Lat., from Gk. Koa/iaf, Kosmas) and DA'MIA'NUS (Lat., from (ik. Aa/innui). Two Arabian brothers of the third century, Christian martyrs under Diocletian. They prac- ticed physic without fee at ^Egea in Cilicia, and, having refused to sacrifice on pagan altars, were beheaded in 303. Their day in the calendar of the Roman Church is September 27. They are honored as the patron saints of physicians and apothecaries. A short-lived order of knights spiritual, named after them, was instituted dur- ing the Crusades. COSMAS OF PRAGUE (c. 1030-1125). A Czech historian, dean of the cathedra! at Prague. His works, particularly his Clironica Boi'm- orum, printed in the second volume of the Fcmtes Serum Bohcmicarum (Prague, 1874), constitute a very complete and accurate record of the history of the times. COSMATI, kos-mil'te. A family of Roman media>val artists, named popularly the Cosmati, from Cosmas, a prominent member. It was founded about a.d. 1140, by Laurentius, con- tinued by his son Jacobus, his grandson, Cos- mas, and a considerable number of other descendants until about 1330, when it dis- persed w-ith the departure of the popes for Avignon and the fall of Rome as an artistic centre. The specialty of this school was the use of rich mosaic inlay in geo- metric patterns in architecture and church in- teriors and furniture; a style often called Cosmati work. But it was not confined to this family, being a style common to all the other family groups of artists of medi.fval Rome and its neighborhood, such as the families of Paulus and Vassallectus. The beautiful cloisters of Saint ,Tohn Lateran and Saint Paul's in Rome are the most familiar of their large works. The choir-seats at San Lorenzo, the tabernacles at Santa Cecilia and Saint Paul's, the pulpits at the Aracoeli, the tombs at the ilinerva and Santa Maria Maggiore, the paschal candlestick at Santa Cecilia, the pavements of these and man}' other Roman churches, show the versatility and universal use of this style. But most of the finest works are scattered throughout the prov- ince, at Civita Castellana, Corneto, Alatri, An- agni, Alba, Ferentino, Terracina, and other cities. The architectural as well as the decora- tive work was executed by these artists. That the style was Roman is shown by the inscription of 1229 in the charming cloister of Sassovivo in Umbria, where the artist calls it Roman irork. However, there were two other contemporary Italian schools which produced similar work: that of Campania, with centres at Salerno, Sessa, and Gaeta ; and that of Sicily, in the churches of Palermo, Monreale, CefaliJ. and others. Consult: Boito, Architetfura Cosmatesca (Milan) ; Frothingham, "Notes on Roman Artists of the Middle Ages" (in early volumes of Americrm Journal of ArclKVolor/i/) . G. Clausse has recently published a very full account of this Roman school ; see his "Les Cosmati." in Revue de I'nrt clvHten. vol. xlvi. (1807) ; Lcs marhriers 7'omains (Paris. 1807). COSMETICS (Gk. KnafivriKdc, l-osmetikos. skilled in adorning, from K6n//n(. kosmos, order, world, universe). Preparations used on the skin or hair to beautify or improve their appear- ance. They include face-powders, such as bloom of almonds and bloom of roses, which impart a led color to the skin; carmine, which is used as a rouge for the i;omplexion; pearl white, which is a preparation of bismuth, and poisonous; and perfumed starch or chalk. The kohl of the Egyp- tians is suppo.sed to have been a preparation of stibnitc or antimony sulphide: it is still used by Oriental ladies for painting the eyebrows. Hair-dyes, which are in many cases preparations of lead and perfumes, may also be classed as cosmetics. The great objection to cosmetics, and especially to face-powders, is their tendency to fill up and clog the pores of the skin, and thus prevent free passage of gases and vapors, which is so essential to the preservation of any animal organ in a thorough state of health. See also Perfumery. COSMIC DUST ( Fr. cosm ique, Lat. eosmicos, Gk. wi(Tu(m)f, kosinikos, cosmic, from Koauni, kosmos, order, world, universe). Finely divided matter that falls to the earth from extra-terres- trial regions. It is probably similar in nature to meteorites, although much of 'the dust that reaches the earth's surface from the outer por- tions of the atmosphere is volcanic. Minute spherules of metallic iron and particles of min- erals have been found in the deposits covering the floor of the deep sea, which are ascribed to cosmic origin. Such particles fall all over the earth, but it is only in the deeper ocean basins, remote from land, that they can accumulate in sufficient quantity to be detected. COSMOG'ONY (Gk. Koa/in-jwia. kosmogonia, from Kurruor, kosinos., order, world, universe -{- •jiin/, gone, birth, origin). A name used by astronomers to designate theories concerning the origin and development of the solar system, stel- lar systems, or the universe in general. Many remarkable facts connected with our solar system tend to show that its present condition cannot be the result of a purely accidental action of natural forces. Thus, the orbits of all the im- portant planets are very nearly circular, and are situated nearly in the same plane; the direc- tions of the planets' motions in their orbits are the same for all ; all the planets, with the prob- able exception of Uranus and Xeptune. rotate in the same direction on their own a.es, and that direction is the same as the direction of their orbital revolutions, etc. Even the planetary satellites share in these peculiarities of the solar system ; the planes of their orbital revolutions about the primary planets are always i-ery near the corresponding planes of the planets' own axial rotations, and the directions of the satel- lites' revolutions also coincide with the direc- tions of the planets' axial rotations. The Nebul.k Hypothesis. Kant and Laplace have given us the well-known 'Nebular Hypothe- sis:' later developed by Sir W. Herschel, to accoimt for the state of affairs existing in the solar system. According to this hypothesis, the material composing the system was originally a mass of intensely hot nebulous or gaseous mat- ter that tended to assume a rotating globular form under the action of gravitational forces. Gradually the mass contracted, and successive rotating rings of matter were from time to time, as it were, left behind. These rings, in turn, broke up. and the matter of each formed a plane- tary system in which again rings and satellites could' form just as in the parent nebular mass.
