Hot chilies are members of the nightshade family, along with all
other sweet peppers, potatoes, tomatoes, and eggplant. The
chemical that makes chilies "hot" is capsaicin; it is mostly
found in the seeds and pale veins along the insides of the
chili. "Hot" is not a taste the way salty or bitter are. Tastes
are detected with the taste buds only, while capsaicin is an
irritant that affects any part of the skin and especially mucous
membranes. Sugar isn't sweet if it gets in your eye, but
capsaicin is still hot as many of us know from unfortunate
experience of touching an eye with a finger used to handle chili
peppers while chopping. In traditional Mexican cooking, the type
of chili called for in a recipe is specific. A sauce originating
in one village might contain three ancho chilies and two pasilla
chilies, while a similar sauce from another region might insist
on one large mulato chili and two chilies negro. Cookbooks offer
substitutes -- if you can't find this, use that one instead. To
confuse the issue fur