"High Society," an exhibition opening today at London's Wellcome Collection museum, examines the history of opium, from pre-biblical practices to today's entire prohibitionist drug market, which is worth an estimated $320 billion per year, according to the United Nations. One of the aims of the exhibit is to de-stigmatize today's illegal drugs and show there is more to the subject than visitors may have thought. After all, substances that many people ingest freely today — alcohol, caffeine and tobacco — have all been criminalized in years past or are still illegal in some parts of the world.