Indre visits Dr. Bruce W. Smith, PhD, at the University of New Mexico's psychology department. He is an expert in the power of positive thinking and the placebo effect. "I think it is really important for us to talk to someone who has studied the power of positive thinking," says Indre.

"When you get some kind of a treatment that doesn't have an active ingredient, but you think it does and it helps you, then that's what's called the placebo effect. Optimism has been something that's been associated with reduced stress response???your immune system might be working better. And then [you] get even more reinforced for that???this positive attitude that can help," says Dr. Smith.

Indre explains that although she does believe in the power of faith and prayer, she still feels there is something special about Chimayo, physically. She sets off to analyze the dirt. Geo-Analytical Chemist Mehdi Ali, PhD. arrives to take some samples for testing in the lab. In the meantime he performs a simple field test that returns a positive result: the Chimayo dirt is high in calcium carbonate, which is an element in medicines like antacids, which make people feel better for conditions such as heartburn.