Why the lick salt-drink tequila-bite a lime shtick?

Dear Cecil: What is the origin of the custom of drinking tequila after licking salt off your hand and afterwards biting into a slice of fresh lime? What does the salt do, anyway? Is it true that tequila is made from the same plant as mescaline? Linda T., Los Angeles

Cecil replies:

Get ready for this. Mescaline is made from what the plant botanists call Lophophora williamsii. Tequila is made from several species of the genus Agave. The term “mescal” is used as an informal name for both types of plant, even though they are of different genera. So, while you could say that both tequila and mescaline are manufactured from the mescal plant, you couldn’t say they are manufactured from the same plant. To add to the confusion, tequila is classified as a Mexican brandy, and the generic name for Mexican brandies is…mescal! Aren’t you glad you asked?

Mexicans have long known that a little sodium chloride on the tongue can help to mollify the fiery flavor that characterizes much of their food. They use salt when downing chile peppers, for example. By the same token, citrus juices of various kinds have long been used to kill the aftertaste of the more potent forms of alcohol. For example, poor black folks in the U.S. used to cut their port wine with lemon juice. The Gallo wine company noticed this and began marketing Thunderbird, a white port-citric acid mixture. Anyway, when tequila came to the U.S., the salt and lime (or lemon) bit came with it.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.