Last Saturday afternoon, a naked man gnawed off most of the face of a half-naked man on a Miami causeway. He continued chewing even after police shot him and did not stop until they shot him dead.

Things like that don’t happen everyday – not even in Miami – so quite naturally the horror story has been picked up by every flavor of media around the world. The most sensational – and I don’t mean that in a good way – coverage came from local TV station CBS4 (WFOR-TV). On the day Rudy Eugene attacked Ronald Poppo, CBS4 relied on the musings of the president of the Miami Fraternal Order of Police and an emergency room physician – neither of whom attested to having firsthand knowledge of the case – to speculate that the attack was caused by a new kind of LSD, by a mixture of drugs, or by “bath salts,” the street name given to the many quasi-legal, over-the-counter stimulant concoctions that are packaged and sold under such wacky brand names as “Ivory Wave,” “Vanilla Sky,” “White Cloud” and “Zoom.”

Before any criminal lab could determine that Rudy Eugene had drugs in his system, some outlets, including the Guardian, the New York Daily News and CNN were seizing on CBS4′s reporting to vilify a “new” drug and its users, exaggerate the peril it presents and launch a new drug panic. To believe the early press accounts about bath salts – recall last year’s story of a West Virginia man found in bra and panties next to his neighbor’s murdered goat – madness comes in a $20 package of powder, the product gives its users superhuman strength, and they may have turned a 31-year-old man into a flesh-eating zombie.

To assist the press in its coverage I offer this brief bath-salts primer. I don’t want to overstate its worth – any skeptical journalist with access to the scientific literature could produce such a primer in an afternoon. That the press hasn’t bothered to produce such a primer speaks volumes about how serious they are in covering the drug beat.

Reporting on bath salts is complicated by the fact that bath salts aren’t one thing: They’re whatever a drug entrepreneur dumps into colorful bags and sells through head shops, convenience stores, and over the Internet as “bath salts,” plant food” or “air freshener.” Promoted by word-of-mouth, bath salts are supposed to deliver a high similar to that of methamphetamine, cocaine and even the “entactogen” MDMA. Bath-salts marketers make certain to label their products “not for human consumption” because, as this July 2011 Department of Justice “situation report” (pdf) explains, the Food and Drug Administration can prosecute anyone who introduces into interstate commerce a compound that’s marketed as a substitute for either a licit or illicit drug, no matter what the compound is composed of.