An investigation into the use of "synthetic marijuana" at the U.S. Naval Academy has resulted in the expulsion of eight midshipman in 2011, a number academy officials say will increase in the months ahead. This raises several interesting questions, the most pressing of which is: what the heck is "synthetic marijuana"?

The Washington Post describes it as "an herbal potpourri sprayed with chemicals that, when smoked, produces mood-altering effects" and has the added bonus of not being detectable in most drug screenings. A 2010 Newsweek article traces the origins of the drug--also known as K2 and Spice--back to the mid-1990s, when a Clemson University chemist named John Huffman synthesized JWH-018, a chemical "structurally similar to THC, the active ingredient in pot, and apparently quite a bit more potent." It wasn't long before word of Huffman's discovery leaked out and users with access to the chemical began "spraying it onto varying mixes of dried herbs, flowers, and tobacco leaves."

According to the Post story, use of the substance is "rising at an alarming rate" throughout the armed services. Midshipman in particular can't seem to get enough, smuggling the faux-weed onto campus. One off-campus apartment was turned into a "synthetic marijuana party house" and is still said to be in operation. Officials only realized the extent of the problem when they seized a sheet of paper from a former midshipman outlining "an apparent plan for a synthetic marijuana ring." In addition to the names of potential customers, the document outlined plans for an off-campus party house "outfitted with a lava lamp, big-screen TV, 'stocked fridge,' dance floor, strobe lights and a 'giant bong.'"

And presumably lots and lots of herbal potpourri.