archbishop of Mainz, and remained in the possession of the electorate till 1802, when it came into the possession of Prussia. In 1808 it was the scene of the memorable interview between Napoleon and the emperor Alexander I. of Russia, at which the kings of Bavaria, Saxony, Westphalia and Wurttemberg also assisted, which is known as the congress of Erfurt. Here in 1850 the parliament of the short-lived Prussian Northern Union (known as the Erfurt parliament) held its sittings. In 1902 the 100th anniversary of the city's incorporation with Prussia was celebrated. See W.J.A. von Tettau, _Erfurt in seiner Vergangenheit und Gegenwart_ (Erfurt, 1880); C. Beyer, _Geschichte der Stadt Erfurt_ (Erfurt, 1900); and F.W. Kampschulte, _Die Universitat Erfurt in ihrem Verhaltnisse zu dem Humanismus und der Reformation_ (1856-1858). For a detailed bibliography see U. Chevalier, _Repertoire des sources. Topo-bibliographie_ (Montebeliard, 1894-1899), s.v. ERGOT, or SPURRED RYE, the drug _ergota_ or _Secale cornutum_ (Ger. _Mutterkorn_; Fr. _seigle ergote_), consisting of the sclerotium (or hard resting condition) of a fungus, _Claviceps purpurea_, parasitic on the pistils of many members of the Grass family, but obtained almost exclusively from rye, _Secale cereale_. In the ear of rye that is infected with ergot a species of fermentation takes place, and there exudes from it a sweet yellowish mucus, which after a time disappears. The ear loses its starch, and ceases to grow, and its ovaries become penetrated with the white spongy tissue of the mycelium of the fungus which towards the end of the season forms the sclerotium, in which state the fungus lies dormant through the winter. The drug consists of grains, usually curved (hence the name, from the O. Fr. _argot_, a cock's spur), which are violet-black or dark-purple externally, and whitish with a tinge of pink within, are between 1/3 and 1-1/2 in. long, and from 1 to 4 lines broad, and have two lateral furrows, a close fracture, a disagreeable rancid taste, and a faint, fishy odour, which last becomes more perceptible when the powder of the drug is mixed with potash solution. Ergot should be kept in stoppered bottles in order to preserve it from the attacks of a species of mite, and to prevent the oxidation of its fatty oil.