At the mayfair theater in New York City on Dec. 2, 1959, opening-night audiences of Behind the Great Wall, a documentary on China, got a whiff of Aromarama, a process where scents were added to the filmgoing experience through the theater\u2019s air-conditioning system. Sadly, the electronic filters that were supposed to remove the odors didn\u2019t, and the audience choked through the accumulated fumes of the process\u2019s debut?and finale. Rival Smell-O-Vision, which released scents through mini-atomizers between rows of seats, premiered a month later in the appropriately titled Scent of Mystery at Chicago\u2019s Cinestage Theater, but it met a similar fate. Adding scents to movies was so unsuccessful that the concept wasn\u2019t revived until 21 years later, when John Waters distributed scratch-and-sniff cards to Baltimore audiences of his 1981 film Polyester. Mercifully, it was again put to rest. Until now.New Delhi native Sandeep Jaidka has patented a system in which films can be encoded with digital signals that cause scents of waterfalls, gardens and kitchens, among other things, to be emitted in the theater. When a film reaches a particular scene, say on top of a mountain, binary signals are sent to a decoding device, which releases the proper blend of gases and perfumes to create the smell of a mountaintop and lowers the room temperature, to create an appropriate chill. The odors are removed through vents in the theater, and the device, capable of detecting lingering smells, knows not to release new ones before old ones are cleared.Jaidka described his device as "very simple" in an interview with Reuters earlier this year. And it will have to be, to gain the widespread adoption its predecessors did not. If it fails to catch on, we still won\u2019t know what a flash in the pan smells like.