And have you ever wondered why the dirty coins thrown into the fountains now quickly turn shiny and bright? The 1999 refurbishing added a potent new dose of oxidizers, anti-calcifiers, anti-fungals, antibiotics, and anti-foliants to the Trevi waters. The purpose of the heady chemical cocktail is to keep the fountain itself clean and healthy. Pipes should not corrode and clog so quickly, summer algal blooms should not happen or at least should be much less frequent, the water should not get cloudy on sunny days, and even really dirty young tourists shouldn't leave a ring around the tub when they occasionally fall or jump in. I don't suppose the water is truly poisonous, but it may well clean your pipes in an unpleasant way if you actually drink it.
The Trevi Fountain, or at least a fountain at its location, has a long history. Most sources agree that it gets its name from the three streets (tre vie) that have converged at the piazza since antiquity. But another legend, immortalized in the fountain's decoration, says that a young virgin named Trivia showed Roman soldiers the spring from which Agrippa later drew water for his baths neat the Pantheon. Agrippa is said to have named both the Vergine aqueduct and its nearby fountain after Trivia. At any rate, in 1453 Pope Martin V erected a small but elegant fountain on the site as part of his project to revitalize Rome. Urban VIII restored the fountain 200 years later getting the funds from a much-derided tax on Roman wine consumption.
The present fountain was started in 1732 when Clement XII Corsini picked Nicola Salvi's design, which was said to have been inspired from a design by Bernini. There were rumors of corruption in the choice -- according to his detractors, Salvi was better known as a poet than as an architect. He produced a flamboyantly Baroque fountain, which incorporated the whole façade of the Palazzo Poli and covered almost the entire piazza in front of the Palazzo. Construction took thirty years, and Salvi didn't live that long.
A new master, Giuseppe Pannini, altered the plans and substituted allegorical statues personifying Abundance and Salubrity (health and well being) for Salvi's planned Agrippa and Trivia. They fill the side niches flanking Pietro Bracci's central statuary group, Neptune (or Ocean) on his aquatic chariot. The horses, one wild and angry and the other calm -- said to depict the two aspects of the sea -- are led by two Tritons. Reliefs above the Abundance and Salubrity statues show Trivia revealing the source of the Acqua Vergine and Agrippa approving the plans for the aqueduct. At the top are statues of the Four Seasons and the Corsini arms supported by two smaller female statues by Paolo Benaglia supposedly related to Corsini family history.
The fountain was cleaned and restored for the first time from 1989-91, but it needed another once-over by 1999. The second cleaning was completed in time for the 2000 Jubilee, much to the surprise of Romans and foreign residents.
Cynics say that the custom of chucking a coin into this particular fountain to ensure a return trip to Rome was started in the 18th century as a way to collect money for neighborhood "charities." But coin-tossing into large fountains (as well as smaller "sources", wells, or springs) certainly became a prevalent custom in Mediterranean cultures almost as soon as coin making began. A big new fountain like the Trevi would immediately be a prime target for small change: it didn't have to be "started" by anyone. Drinking the water, when it was still salubrious, was said to have the same effect as tossing a coin.
The Trevi coin custom got its biggest boost from the 1954 movie "Three Coins in the Fountain" and from the Academy Award nominated song hit of the same name. You can read about that movie and, if you want to embarrass your kids by singing aloud at the fountain, you can get the song lyrics at Internet sites listed below. And remember that the three coins in the song were thrown by three different women -- you only need to throw one coin per person. There is also an Internet link for Fellini's much less joyous 1961 movie, "La Dolce Vita", which also featured the fountain.
Old prints of the previous and current fountains with some modern photos: http://www.siba.fi/~kkoskim/rooma/pages/FTREVI.HTM
A short description with a good picture: http://www.1000plus.com/Italia/trevi.htm
Lyrics for "Three Coins in the Fountain": http://persweb.direct.ca/fstringe/oz/t22528.html#Y
Movie facts for "Three Coins…": http://aol.eonline.com/Facts/Movies/0,60,46111,00.html
"La Dolce Vita": http://aol.eonline.com/Facts/Movies/0,60,4937,00.html