CannaCon is an enormous cannabis-business convention that was held last month at the absolute worst place in Seattle: the cruise ship terminal. Yes, I know the cruise industry stimulates our economy, but if forced to choose, I'd way rather be forced to mingle with, say, Amazon brogrammers in South Lake Union than sunburned Oklahoman anti-choice warriors who are on a never-ending quest for the Gum Wall and "that place where they throw the fish."

CannaCon—"Where the Cannabis Industry Does Business"—was one of those events where thousands of glossy info sheets are handed out for no real purpose other than to make the Lorax cry. Plastic gift bags full of disposable promotional junk are foisted upon you left and right. Like most trade conventions, it is an environmental nightmare. I even tried to take public transit there and was forced to walk dejectedly across the vast paved expanse of the pier while enormous charter buses shuttling convention-goers to and from the parking lot blew by me.

All these gripes aside, CannaCon had some redeeming qualities. Free candy at nearly every other booth, for example. But the most exciting thing I found at CannaCon this year was the Wirtshafter Collection, Don E Wirtshafter's private collection of vintage cannabis medicine bottles.

Wirtshafter, an Ohio lawyer, cannabis advocate, and hemp pioneer, was there to give a talk entitled "The First Golden Age of Cannabis Medicines." Sadly, his fascinating exhibit, relegated to a small section of wall near one of the convention's bajillion extraction-technology booths, did not feature the actual bottles, only photographs.

The bottles themselves are worth hundreds of thousands of dollars, and trying to properly secure them with hundreds of thousands of stoners milling about would have been damn near impossible, Wirtshafter said. However, despite the fact that the exhibit that I'd trekked across that lonely asphalt desert for wasn't really an exhibit, it was still worth the walk.

Wirtshafter began collecting the bottles in the 1990s, his curiosity about cannabis's legitimacy as a medicine sparked by his involvement with a project in the Netherlands to grow medicinally focused strains of cannabis. The bottles, he said, were his way of sticking it to all the haters.

"I kept hearing people claim that Cannabis had never been accepted as a medicine in the United States," reads his collector's statement. "I set off to prove this wrong by collecting the remaining evidence not lost to seventy-five years of prohibition."

He certainly succeeded. Staring at the photograph of a bottle of cannabis extract tablets manufactured by Eli Lilly and Company, the same company that made the insulin in my pocket, was, for lack of a better word, trippy. There's a lot of talk these days about making cannabis use normal. Wirtshafter's collection is a tangible reminder that, until our government banned it, it was.

He says there was a concerted effort to destroy all evidence of cannabis products after they were prohibited by the Marihuana Tax Act of 1937, as Orwellian as that sounds.

"This is an area of history that wasn't forgotten—it was purposely removed from our memories," he said. "In 1937, they made the prohibition against cannabis so complete that they went after museums, schools, and anybody who would have even things as collectibles. They really tried to suppress all evidence of human use of this plant."

Its medicinal use, he adds, was particularly targeted in this campaign of erasure.

"This medical stuff was especially purloined," he said. "It's just not there. It was wiped out of the pharmacopoeia, not in any of the catalogs, none of the pharmaceutical companies admit to having these things. Yet here we are with all the major pharmaceutical companies of the day producing cannabis."

Pharmacists, he notes, had no warning of the ban, and cannabis products were still sitting on shelves when the government started confiscating them. While many of Wirtshafter's finds came from old pharmacies—he had a source whose job was shutting down defunct pharmacies and selling off their inventory—his largest take was from the widow of a Texas revenue agent who had decided to keep a bunch of the bottles in a closet instead of taking them in to headquarters.

I've heard a variety of reasons cited for that original cannabis prohibition, ranging from US Bureau of Narcotics head Harry J. Anslinger being an unabashed racist to William Randolph Hearst's heavy investments in nylon and concurrent desire to snuff out the hemp industry.

Whichever of the many theories you subscribe to, Wirtshafter's collection is clear evidence that prohibition was not a medically driven decision. Buying pot was, at some point, like buying Tylenol. Interestingly enough, Wirtshafter told me that early formulations of cannabis medicine wouldn't be much different from an infused oil product that an MMJ patient might take today. Except there was one interesting difference: As a pain reliever, cannabis was often combined with opioids and capsaicin (the chemical in chili peppers that makes them spicy and has a numbing effect).

That would seem to prove that the rise of opiate painkillers in the late 1930s—the distant beginning of our country's dark love affair with the stuff—was more a result of prohibition than a cause, neatly disproving one of those prohibition conspiracy theories. Cannabis, said Wirtshafter, actually has a restorative effect on opioid receptors, meaning that, when used in conjunction, lower doses of opiates are needed and tolerance remains lower.

This is corroborated by a 2004 article in the journal Life Sciences that notes, "THC, the major psychoactive constituent of marijuana, enhances the potency of opioids such as morphine in animal models." The article also describes "an intimate connection between the cannabinoid and opioid signaling pathways in the modulation of pain perception." Couple that with a recent study from Columbia University that found that pot use helped to alleviate withdrawal symptoms for recovering opiate addicts, and the argument for pot as analgesic medicine—the argument that drove Wirtshafter to collect all those bottles—becomes quite strong.

Prints are for sale. More information and pricing at cannabismuseum.com.