Urine was a must-have detergent for any ancient housewife. Containing ammonia, it is actually perfectly suitable for bleaching linen and cleaning. Not only the ancient women whitened their husbands’ togas with the wonderful liquid, they also bleached their teeth and hair. It appears that red and blonde were the most popular hair colours in ancient Rome. To obtain this last one, women rubbed in pigeon excrements mixed with ashes and then washed a head in a pot of urine. Smelly - but prettily. Leave alone women’s quirks, urine was widely used for tanning leather, making toothpaste and bleaching fabriques.
At a certain point - namely around 70 AD, when Roman economics was doing very poorly, emperor Vespasian came up with an odious thought to establish a so-called “Urine tax”. You see, up until then ordinary citizens used to pee into simple pots that were emptied into cesspools. After the new tax was introduced, public latrines were equipped with urine collectors, from which this precious product could be sold as a source of ammonia.
Vespassian’s son Titus was highly displeased by nature of the tax, which he considered to be disgusting. His father then passed him a gold coin and asked whether he felt offended by its smell. When Titus said "No," Vespassian replied, "Yet it comes from urine". Hence the expression “Pecunia non olet - money does not smell”.