or excises which obstruct very much the most important of all branches of commerce, the interior commerce of the country. In some small states duties similar to those passage duties are imposed upon goods carried across the territory, either by land or by water, from one foreign country to another. These are in some countries called transit-duties. Some of the little Italian states which are situated upon the Po and the rivers which run into it derive some revenue from duties of this kind which are paid altogether by foreigners, and which, perhaps, are the only duties that one state can impose upon the subjects of another without obstructing in any respect the industry or commerce of its own.

The most important transit-duty in the world is that levied by the King of Denmark upon all merchant ships which pass through the