Don’t believe everything you hear.
I recently watched an old episode of Midsomer Murders where the corpse was dead but the pathologist was dead wrong. An individual had died while on a trip to China and the body was sent home to the UK for burial. When he exhumed the body and did an autopsy, the pathologist found ground glass in the stomach. He said feeding ground glass to victims was an old Chinese method of poisoning and concluded that the death was a murder.
I knew that ground glass is not a poison, and eating it is not deadly. That myth has even been debunked on Snopes. I thought ground glass poisoning was widely known to be a myth, but my husband was watching the episode with me and I was surprised when he said he thought it was true. I figured if he believed it, lots of other people probably did too, so I thought it would be useful to set the record straight.
Australia’s “Dr. Karl” (Karl Kruszelnicki) also wrote an article debunking the myth. He points out that if the glass is not finely ground, the person eating it will notice sharp particles in the food and will stop eating it. If it is finely ground, ingesting it is as harmless as ingesting sand. Back in 1642, the physician Sir Thomas Browne fed ground glass to dogs and found it did them no harm. More recently, in 1916, a poisoner in New York testified that he had tried to use ground glass to kill people, but it had proved to be useless. The fictional depictions of ground glass murders in books, stories, movies, and television often show rapid deaths with bleeding from various body orifices, but that wouldn’t happen. Sharp particles of glass might lacerate the lining of the gastrointestinal tract, but the bleeding would be slow and likely to result in anemia and fatigue rather than in anything dramatic.
Todd Robbins eats light bulbs; I saw him do it at The Amazing Meeting. He explains that it is not a magic trick, but an old sideshow performance. The lightbulb is very real; he even plugs it in and lights it up before he eats it, to rule out the possibility of a fake lightbulb. He crunches the glass into a fine powder with up-and-down movements of his teeth, carefully avoiding movements that might allow a glass shard to slice into tissue, and then he actually swallows the resulting ground glass. He says he follows a special diet to minimize the chance of harm.
The picture above shows an Indian lawyer, Dayaram Sahu, who has been eating glass for 40 years for fun. He calls it an addiction, and says it is a dangerous habit that has harmed his teeth and health. He is trying to curb his habit and he is not asking others to try it.
You can learn how to eat glass safely by watching this YouTube video. But DO NOT TRY THIS AT HOME.
The important lesson here is never to assume any claim is true no matter how plausible it seems, but to always do some fact-checking first. Believing ground glass is a murder weapon may not harm you, but false beliefs can be harmful. If nothing else, knowing that this is a myth might help you win a Trivia Night contest.
Another lesson is not to get your scientific information from movies or fiction; but you already knew that, right?