Explanation: In the rule of the Roman Emperor Vespasian, a tax was placed on urine collection!
Urine was used in bleaching, cleaning, and tanning (it's the ammonia), so it was actually a valuable commodity. Terracotta amphorae were placed around the city of Rome where citizens could relieve themselves like CIVILIZED people, and Vespasian implemented a tax on those who collected those pisspots.
His son, Titus, thought it was beneath the dignity of the Res Publica to impose a tax on such a crude matter. Vespasian, supposedly, waved a gold coin made from the tax under his nose and asked him if it smelled of urine, from which we get the modern Latin phrase Pecunia Non Olet - "Money doesn't smell"!