The Wealth of Nations by Part 5 Chapter 2 Page 106

inundations, and is thereby exposed to extraordinary expenses. Upon such occasions the people assemble, and every one is said to declare with the greatest frankness what he is worth in order to be taxed accordingly. At Zurich the law orders that, in cases of necessity, every one should be taxed in proportion to his revenue- the amount of which he is obliged to declare upon oath.

They have no suspicion, it is said, that any of their fellow-citizens will deceive them. At Basel the principal revenue of the state arises from a small custom upon goods exported. All the citizens make oath that they will pay every three months all the taxes imposed by the law. All merchants and even all innkeepers are trusted with keeping themselves the account of the goods which they sell either within or without the territory.