Revenue from the mines, especially from the Spanish silver-mines.
5.

Duties on imports and exports.

And, 6.

A duty on enfranchised slaves.
The receipts were all paid into the national treasury, and the senate had the uncontrolled direction of the general expenditure, as well as the regulation of the amount of imposts.

The officers employed to manage the affairs of the revenue, were the quaestors, chosen annually, and under them the scribes, who held their situations for life.