Medicine: St. Anthony's Fire

Not in years had France seen such rain. Farmers slogged stolidly out to their fields to harvest the sodden crops, mill the grain and send it on its way. In little (pop. 4,400) Pont-Saint-Esprit, perched on a bluff along the River Rhone in southern France, the townspeople sat glumly in their bistros sipping wine, watching the swollen river slip past the medieval bridge which gives the town its name.

Then, without warning, pain and sudden death clutched Pont-Saint-Esprit. On a Saturday night three weeks ago, the town's doctors began getting calls from people complaining of heartburn, stomach cramps and fever chills. At...