The buttons-coins of Egyptian campaign

In the XIX century, on the buttons of military uniforms was impressed with the number of the company or regiment to which the soldier belonged.
In this regard, there is a curious anecdote concerning the Napoleonic era: at the end of the campaign of Egypt (1798), Napoleon’s army was left without buttons. This is because the soldiers used the buttons as currency, making it appear to the Egyptians that the number written on the buttons was referring to a value in francs (or cents).