In 1415 the Aargau region was taken from the Habsburgs by the Swiss Confederates.
In 1798 the Bernese bit became the canton of Aargau of the Helvetic Republic, the remainder forming the canton of Baden.
In 1803, the two halves (plus the Frick glen, ceded in 1802 by Austria to the Helvetic Republic) were united under the name of Kanton Aargau, which was then admitted a full member of the reconstituted Confederation.
Hydrated sulphates occur at several localities in the province of Madrid and in other provinces of Spain, and at Miihlingen in Aargau, and copious deposits of glauberite, the double sulphate of sodium and calcium, are met with in the salt-mines of Villarrubia in Spain, at Stassfurt, and in the province of Tarapaca, Chile, &c. A native nitrate of soda is obtained in great abundance in the district of Atacama and the province of Tarapaca, and is imported into Europe in enormous quantities as cubic nitre for the preparation of saltpetre.
In 1415 Baden (with the Aargau) was conquered by the Eight Swiss Confederates, whose bailiff inhabited the other castle, on the right bank of the Limmat, which defends the ancient bridge across that river.