Page:Collier's New Encyclopedia v. 10.djvu/166

URINE 138 URSA MAJOR for solution, to which it imparts a very feeble acid reaction. It is insoluble in alcohol and ether, but dissolves in con- centrated sulphuric acid, which deposits it in a hydrated condition or dilution. The urates of the alkalies are much more soluble than the acid itself. Uric acid is dibasic, giving rise to acid and neutral salts. By being submitted to heat, uric acid breaks up into a number of com- pounds, but the remarkable number of definite and crystallizable substances which it gives rise to, when treated with various oxidizing agents, present the highest physiological interest, inasmuch as the great changes which occur in the animal economy under the influence of vitality are always accompanied by oxi- dation. URINE, the secretion of the kidneys, the chief fluid excretion of man and of the higher animals. Healthy human urine is a transparent light amber- colored liquid, having a saline taste, a peculiar aromatic odor, an acid reaction, and a density varying from 1.010 to 1.025. Its chief constituents are urea, uric, lactic, and hippuric acids, and crea- tine, together with calcium and magne- sium sulphates, chlorides and phosphates, alkaline salts, certain imperfectly known principles, and a coloring substance. The urine contains the liquid portion of use- less and noxious residuum left after the assimilation of whatever is useful to the structure. Morbid states of the urine occur — the aqueous, the subaqueous, the lithic, the phosphatic, the purpuric, the albuminous, and the saccharine. Aqueous urine, with a diminution in its solid contents, is passed in large quantity by nervous and hysteric persons, especially when they approach old age. Subaqueous urine, in some respects the opposite of the first, carries off an unduly large proportion of solid matters, and exists chiefly in de- cline of the bodily powers, which it tends to accelerate. Lithic urine deposits a pink or purple sand or "gravel," con- sisting of lithia; its ultimate tendency is to produce lithic calculi. Phosphatic urine contains an excess of phosphatic salts, and deposits a white earthy or chalky powder. Purpuric urine deposits a lateritious sediment. Albuminous urine deposits albumen ; sometimes it is an un- important, but at other a very formidable disease. Saccharine urine is an attendant on diabetes. The mechanism by which the urine is secreted is apparently of a double kind: (1) uriniferous tubules, which seem to be actively secreting struc- tures, and (2) the Melpighian capsules, which appear to act rather as a filtering apparatus. URQUHART, DAVID, a Scotch econ- omist; born in Braelangwell, Scotland, in 1805; was educated at Oxford University after which he entered the diplomatic service; was secretary of the British embassy at Constantinople in 1835-1836. He was a representative for Staf- ford in Parliament in 1847-1852. During most of his public career he antagonized the Eastern policy of Lord Palmerston, which he held was subservient to the am- bitious wishes of Russia. His publica- tiens include "England, France, Russia, and Turkey" (1835) ; "The Spirit of the East, a Journal of Travels Through Roumeli" (2 vols. 1838) ; "The Progress of Russia in the West, North, and South" (1853) ; "Letters and Essays on Rus- sian Aggressions" (1853) ; etc. He died in Naples, May 16, 1877. URSA MAJOR, in astronomy, the Great Bear, the most conspicuous of the 20 ancient northern constellations, its seven leading stars attracting notice all the more conspicuously that there is a certain absence of visible heavenly bodies in the adjacent parts of the sky. The Semitic conception of the constellation was that it resembled a bier with mourn- ers walking behind, and it has sometimes been called specifically Lazarus' bier, the four stars constituting a four-sided figure being the bier and the other three, Mary, Martha and Mary Magdalene, the mourners. It is much like a plow, and ia often called the Plow, the rectangle con- stituting its body, and the three project- ing stars its handle. To other minds it suggests a vehicle, whence it has been called the Car of David, and sometimeg Charles' Wain or Wagon. The four stars standing together are the wheels, and the three behind are the shaft. Another name is the Dipper. But astronomers cling to the old classical conception of a bear, of which the four stars. Alpha, Beta, Gamma, Delta, Ursse Majoris, are the hind quarter, and the three the tail. The remaining portions of the animal are marked out by sundry small stars of the third and fourth magnitude. The Bear was supposed to require a ward or keep- er. The Arabs gave the seven conspic- uous stars names, some of which are still in use. They are called Alpha, Ursas Ma- joris or Dubhe; Beta, Merak; Gamma, Phecda; Delta, Megrez; Epsilon, Alioth; Zeta, Mizar; and Eta, Alcaid, or Benet- nasch. The first two are called pointers, because a line drawn from Beta through Alpha and continued for about five times as far as the distance between them will reach the pole star. Ursa Major is bounded on the N. by Draco and Camelo- pardalis, on the S. by Leo Minor, on the