duchy of Italy, which makes part of the ancient Etruria, excepting some small detached parts, is encompassed by a part of the Mediterranean, called here the Tuscan Sea; the ecclesiastical state; the duchy of Modena; and the republic of Lucca; its extent from north to south being about 116 English miles, and from east to west about 80.

Though some parts of it are mountainous, yet both the hills and dales are covered with vines, olives, citron, lemon, and orange trees, &c. The mountains yield also copper, iron, alum, &c., and some quarries of the finest marble and porphyry. Here is also plenty of corn, rice, saffron, honey, wax, wool, flax, hemp, with mineral waters, rich pasture, salt-pits, sulphur, alabaster, chalcedony, lapis lazuli, borax, amethysts, cornelians, jaspers, quicksilver, crystals, and black slate. In some places the elms and ashes yield manna.

The principal river in Tuscany is the Arno, which has its source in the Apennine mountains, and falls into the sea below Pisa. There are some other smaller rivers.

This duchy fell under the dominion of the Romans about 455 years before Christ. The Ostrogoths possessed themselves of it in the fifth century, and after them the Lombards, who were expelled by Charlemagne anno 800; in consequence of which it became subject to the German emperors, who appointed governors over it. At last the cities of Florence, Pisa, Sienna, and some others, during the contentions between the pope and the emperor, and their respective adherents, the Guelphs and Gibelines, withdrew themselves from the dominion of both, and erected themselves into separate commonwealths. In that of Florence, John de Medici, a popular nobleman, so inflamed himself into the favour of his countrymen, that they invested him with sovereign power. Pope Pius V. conferred the title of grand duke on Cosimo de Medici anno 1570, in whose family the duchy continued until the death of Galileo de Medici, who died anno 1737. The duchy was then transferred to the duke of Lorraine, afterwards the emperor Francis I. in lieu of the duchy of Lorraine, which, by the peace of 1736, was given to king Stanislaus during his life, and then was to be annexed to France. Leopold, the second son of Francis I. and afterwards emperor of Germany, succeeded to this duchy. It is now enjoyed by Leopold's second son, brother to the present emperor of Germany, Francis II. The grand duke's annual revenues are computed at about 500,000l. sterling, arising chiefly from the tenths of all estates that are sold or alienated, and the ground-rents of the houses in Leghorn, and the duties on almost all manner of provisions.

The great duke is absolute in his dominions. His standing forces consist only of three regiments of foot and two of dragoons, and his marine of a few galleys and galleasses; but, in case of necessity, it is said he can bring 30,000 men into the field, and increase his marine with 20 men of war; but it does not appear how he can man them.

The principal places are Florence, Pisa, Leghorn, Sienna, Orbitello, Fiombino, and Arezzo.

Tusk, or Torso, in ichthyology. See Gadus.

Tussilago, Colt's foot, in botany: A genus of plants belonging to the class of Juncaginaceae, and order of Polygama superflua; and in the natural system ranging under the 49th order, Compositae. The receptacle is naked; the pappus simple; the scales of the calyx equal, of the same height as the disk, and somewhat membranaceous. There are 12 species; three of which are indigenous to Britain, the farfara, hybrida, and petasites.

The farfara, or common colt's foot, grows plentifully on the banks of rivulets, or in moist and clayey soils, in England and Scotland.—The leaves are smoked in the manner of tobacco, or a syrup or decoction of them and the flowers (and recommended in coughs and other disorders of the breast and lungs). It seems now to be almost entirely rejected. The downy substance under the leaves, boiled in a lixivium with a little saltpetre, makes excellent tinder.

The petasites, or common butter-bur, is frequent in wet meadows and by the sides of rivers. Its leaves are the largest of any plant in Great Britain, and in heavy rains afford a seasonable shelter to poultry and other small animals. The root dug up in the spring is resinous and aromatic. A drachm of it in a dose has been sometimes given as a sudorific and alexipharmic; but as it possesses those virtues but in a small degree, it has lost its reputation in the shops.

Tutenago, an ore of zinc, containing commonly from 60 to 90 per cent. of zinc, the remainder iron, and a small proportion of clay.