ALLAN, Sir WILLIAM ( 1782-1850 ) . A Scotch painter. He was born in Edinburgh, and studied art in the Trustees' Academy there, and in the schools of the Royal Academy, London. In 1805 he went to Saint Petersburg, and spent several years in various parts of Russia and Turkey, where he acquired material for his first successful pictures. Returning to Scotland in 1814, he devoted himself to Scottish historical painting. This part of his work includes "John Knox Admonishing Queen Mary" ( 823) , "Queen Mary signing her Abdication" (1824), and the "Death of the Regent Murray" (1525), which made him an A.R.A. ln 1834 he re turned to his earlier subjects, and his "Polish Exiles on their Way to Siberia" and "The Moorish Love-Letter" won him a seat in the Royal Academy. Later pictures were "A Slave Market in Constantinople" (1837), "The Battle of Prestonpans" (1842), "Waterloo," from the English side (1844, bought by the Duke of Wel lington), "Peter the Great teaching Shipbuilding to his Subjects" (ordered by the Czar. 1845). Allan became president of the Royal Scottish Academy in 1838, in 1841 succeeded Wilkie as limner to the Queen in Scotland, and was knighted in 1842. His reputation rests on his
skill in composition and dramatic representa tion.
ALLAN'TdiN ( Ultimately derived from allantois).C,H,N,0,. An organic substance found in the allantoic and amniotic fluids, in fetal urine, and in the urine of many animals during a short time after birth. It is a crystalline, solid substance, sparingly soluble in cold water, but dissolving readily in hot water or alcohol. aml in solutions of alkaline carbonates. It may be obtained from the urine of calves by evaporating and letting stand, at ordinary temperatures, until the substance crystallizes out. Chemically, allantoth is the di-ureide of glyoxylic acid. It is one of the most important products of the oxidation of uric acid (allantoln is found in urine after uric acid has been taken internally), and, on the other hand, it may be readily made from urea by prolonged heating with glyoxylic acid. When uric acid is oxidized with potas sium permanganate, allantoin is formed, accord ing to the following chemical equation; Allantoin was first discovered in 1790 by Vauquelin. See URIC ACID.