This one kind of annoys me, since anytime there's a flu or disease of any kind coming out, people toss away any critical thinking skills they have to embrace the latest version of it - based mainly on the cool name, as far as I can tell. After all, anything that thieves used to help them in stealing from corpses, MUST be cool.
The Wiki article IS actually kinda cool, so I'll post it in its short entirety:
Four Thieves Vinegar
From Wikipedia, the free encyclopedia
Four Thieves Vinegar (Vinaigre des Quatre Voleurs) is a concoction of vinegar (either from red wine, white wine, cider, or distilled white) infused with herbs, spices or garlic that was believed to protect users from the plague. The recipe for this vinegar has almost as many variations as its legend.
Vinegar has been used to fight plague since the middle ages, and herbal vinegars have been used as medicine since the time of Hippocrates.
Early recipes for the concoction specifically known as Four Thieves Vinegar sometimes employ a different number of thieves, and in the 18th century the mixture was sometimes just called "Thieves Vinegar" or in at least one instance, "Three Thieves Vinegar." In Italy a mixture called "Seven Thieves Vinegar" is sold as a smelling salt, though its ingredients appear to be the same as in Four Thieves mixtures.
Modern day versions of Four Thieves Vinegar include various herbs that typically include sage, lavender, thyme, and rosemary, along with garlic. Additional herbs sometimes include rue, mint, and wormwood. It has become traditional to use four herbs in the recipeâ€”one for each thief, though earlier recipes often have a dozen herbs or more. It is still sold in Provence. It is also used by modern practitioners of witchcraft to ward off the spells of other witches, or to enhance spells that call for vinegar.
The usual story declares that a group of thieves during a European plague outbreak were robbing the dead or the sick. When they were caught, they offered to exchange their secret recipe, which had allowed them to commit the robberies without catching the disease, in exchange for leniency. Another version says that the thieves had already been caught before the outbreak and their sentence had been to bury dead plague victims; to survive this punishment, they created the vinegar. The city in which this happened is usually said to be Marseille or Toulouse, and the time period can be given as anywhere between the 14th and 18th century depending on the storyteller.
One interesting twist says that "Four Thieves Vinegar" is simply a corruption of the original "Forthave's Vinegar," a popular concoction created by an enterprising fellow by the name of Richard Forthave. Another source, AbregÃ© de tout la mÃ©decine practique, seems to attribute its creation to George Bates, though Bates' own published recipe for antipestilential vinegar in his Pharmacopoeia Bateana does not specifically use the name 'thieves' or 'four thieves.' http://en.wikipedia.org/wiki/Four_Thieves_Vinegar