PROJECTION. 439 PROLAPSUS TJTERI. case perfectly general in its application, while in tlie latter only the projection of the sphere is required. Projections of the sphere are of va- rious kinds, all of which are treated under Map. In mathematics, the theory of projections has reached a high degree of perfection, serving to generalize the ancient geometry. (See Geom- etry.) Its hasis is the investigation and deter- mination of those properties which, being true of a hgure, are also true of its projections, such properties being necessarily dependent, not on the inuynitude, but on the position of tlie lines and angles belonging to the figure. These prop- erties are generally called projectile properties. For instance, the three conic sections (q.v.), the p;uahola, ellipse, and hyperbola, are merely va- rious projections of a circle on a jilane, and all positional properties of the circle are at once, by this theory, connected with similar properties of the three conic sections. The introduction of coordinates has extended the ajiplications of the subject, and it is now employed in solving the problems of ajiplied mathematics. For further information, see the references given untler Geoiietky. For the use of projec- tion in mechanics, consult: Poisson, Traite de Mccaiiiquc (2 vols., Paris, 1811) ; Klein, Theorie des Kreisels (2 vols., Leipzig, 1897-98) ; and Stade and Seidel, Das Wichtiyste uiis dem geo- mctrischen Zeivhnen iiiid dcr Projektionslehre (Leipzig. 1894), PROJECTIVE GEOMETRY. A geometry in which the properties and relations are investi- gated liy means of the theory of projections. See Geometry : Pko.iectiox. PROKESCH-OSTEN", proT^esh os'ten, AjfTOJr, Count (179.3-1870). An Austrian diplomat and author, born at Gratz. He entered the Austrian Army, served in the French campaign in 1813-15, was made professor in the militar}' school of Olmiitz (1810), and, after serving as adjutant to Prince Schwarzenberg (whose memoirs he published in 1822), was sent on diplomatic mis- sions to the East. In Greece and Syria he was very successful, and for his services in bringing about the treaty of 1829 with the Pasha of Akka, whereby Christians were granted many privileges in Palestine, he was ennobled with the title of Von Osten (1830). In 1831 he was chief of stafT in the Austrian army sent to Bologna, and he was Minister to Athens in 1834-49, and to Berlin, with the title of Ambassador, in 1849-52. He was ambassador to the Frankfurt Parliament in 1853-54 and from 1855 to 1871 represented Aus- tria at Constantinople. He was made a baron in 1845 and a count in 1871. His more important works are Eriunerunycn aus Aeyypten iind Kleinnsien (1829-31) and Geschichte des Abfalls der (Iriechen vom turUischen Reich (1821). PROLAPSUS ANI (Lat., falling of the anus). An afl'cction of the terminal portion of the intestinal canal which consists in a protrusion of the mucous membrane of the lower part of the rectum through the anal orifice. When the protrusion includes the whole thickness of the rectal wall the condition is known as prolapsus recti. These conditions may depend on a naturally relaxed condition of the parts, such as exists in infancy, or they may be brought about by violent straining as in cases of costiveness. h.fmorrhoids, and so on. Whenever prolapse occurs, the parts should be washed, and. if possible, replaced Ijy careful pressure with the fingers; and if they do not easily leturn, the fore- finger should be oiled and pushed up into the anus, when it will convey the protruded intestine with it, after which the patient should maintain the recumbent posture for some hours. If the protrusion cannot be returned b}' the above means, surgical assistance should be at once sought. In order to obviate the tendency to prolapse the patient should regulate the bowels so as to avoid costiveness and should sponge the parts, after each evacuation, with cold water. A firm pad is sometimes required to prevent re- currence. Where the trouble persists it may be necessary for the surgeon to provide retraction of the redundant mucous membrane by removing portions of it either by the knife or the cautery. In cases of severe prolapse of the whole of the rectal coats it may be necessary for the surgeon to resect a portion of the rectal wall. PROLAPSUS UTERI (Lat., falling of the womb). The condition in which the womb falls below its natural position in the pelvic cavity and approaches the outlet of the vagina. If the womb appears outside it is known as pro- cidentia, or complete prolapse. Thus we have all degrees of prolapse from a very slight depression to a complete extrusion, and in its descent not only does the womb itself fall down, but it drags with it the vaginal walls, usually a part of the bladder, and less frequently the rectum. The prolapsed portion of the bladder is known as a cystocele, that of the rectum as rectocele. Pro- lapse of the uterus is a very common affection, occurring most frequently in women past middle age who have borne many children; but it is also found in tinmarried women, and rarely in children. The causes are: (1) Rela.xation of the ligaments that normally hold the uterus in place ; (2) weakening of the support lielow due to a loss of tone in the tissues or to injur.v or lacera- tion dviring labor ; ( 3 ) an increase in weight in the uterus, either from congestion or disease ; and finally (4) an increased pressure within the abdo- men forcing the uterus down, as in straining from constipation. The symptoms of this affec- tion arise partly from the pressure of the womb on other organs, partly from the simultaneous displacement of adjacent parts (as the bladder, rectum, etc.), and partly from rcfiex action. Patients with only a slight displacement tisually complain of a sensation of fullness in the pelvis, of weight and bearing down, of dragging pain in the back, these symptoms being aggravated when the upright position is assumed. The treatment varies with the degree of displace- ment. In cases of complete prolapse the uterus should be replaced and retained in position if possible by mechanical means, stich as tampons of cotton or pessaries or rings. In extreme cases removal of the entire organ may be necessary to afTord relief. In cases of moderate severity great improvement is further secured by increasing the general tone of the tissues by tonics and constitutional treatment and by douches and other forms of local applications. The improve- ment in the general health is of great importance. In many instances an operation is necessary for the repair of the lacerated tissues at the pelvic outlet. Where neglected the condition has a tendency to become aggravated and rectal and bladder symptoms make themselves evident.
