Ems, emz, a famous watering place in western Prussia. It is situated in the valley of the Lahn, twelve miles from Coblenz. The valley is here inclosed by rocky cliffs crowned with woods and vineyards. Old coins, weapons, and other relics found here indicate that it was at one time a Roman post. There are lead and silver mines here, but the town owes its fame to its mineral springs. The waters are warm, ranging in temperature from 70 deg. to 130 deg. F. They are strongly impregnated with carbonic acid gas, and afford relief in cases of chronic catarrh and lung troubles. The city is given over largely to hotels and other accommodations for summer visitors. From 10,000 to 15,000 patients and tourists visit the city each summer. While here for his health in the summer of 1876, King William III, afterward Emperor William I of Germany, was approached by the ambassador of Napoleon III. The Frenchman took advantage of the old king in a casual meeting in a garden, and goaded him unhandsomely, practically giving notice that brought on the Franco-Prussian War of 1871.