The chief towns of the grand duchy are Darmstadt (the capital) and Offenbach in Starkenburg, Mainz and Worms in Rheinhessen and Giessen in Oberhessen. More than two-thirds of the inhabitants are Protestants; the majority of the remainder are Roman Catholics, and there are about 25,000 Jews. The grand duke is head of the Protestant church. Education is compulsory, the elementary schools being communal, assisted by state grants. There are a university at Giessen and a technical high school at Darmstadt. Agriculture is important, more than three-fifths of the total area being under cultivation. The largest grain crops are rye and barley, and nearly 40,000 acres are under vines. Minerals, in which Oberhessen is much richer than the two other provinces, include iron, manganese, salt and some coal. The constitution dates from 1820, but was modified in 1856, 1862, 1872 and 1900. There are two legislative chambers. The upper consists of princes of the grand-ducal family, heads of mediatized houses, the head of the Roman Catholic and the superintendent of the Protestant church, the chancellor of the university, two elected representatives of the land-owning nobility, and twelve members nominated by the grand duke. The lower chamber consists of ten deputies from large towns and forty from small towns and rural districts. They are indirectly elected, by deputy electors (_Wahlmanner_) nominated by the electors, who must be Hessians over twenty-five years old, paying direct taxes. The executive ministry of state is divided into the departments of the interior, justice and finance. The three provinces are divided for local administration into 18 circles and 989 communes. The ordinary revenue and expenditure amount each to about L4,000,000 annually, the chief taxes being an income-tax, succession duties and stamp tax. The public debt, practically the whole of which is on railways, amounted to L19,097,468 in 1907.