The herbai medicine industry is growing at an astounding rate. Trade group estimates suggest that total sales exceeded $4 billion dollars in 1999. Herbai remedies are for sale not just in health food stores, but in supermar kets, drug stores, and even discount warehouses. Along with the proliferation in sales has come a proliferation ofinformation sources. Not all ofthe sources are equally reliable, or even intelligible. Traditional herbalists c1assify thistle and mugwort as "cholagogues," substances used to make the gallbladder con tract and release bile. Medical school graduates are...