Tag Archives: poison

Bezoar Stones

Bezoar Stones also called mad stones, have a considerable history in American folklore. They were thought to have the power to treat or neutralize poisons or venoms in wounds. Those wounds may be from insect stings, poisonous plants, snake bites, and even the bites of rabid animals. Treatment consisted of simply holding the stone up against the wound.

The Old Farmer’s Almanac published a story about mad stones in a 2010 edition. The story referred to a number of instances dating to the 19th and into the 20th century where the stones were used for snake bites and especially bites from rabid dogs.

Also clear from these stories is that the stone only worked if obtained directly from an animal or was received as a gift. Buying and/or selling destroyed the power of the stone, and if stolen would actually cause harm to the thief.

Bezoars are usually golf ball sized concretions of hair and calcium salts taken from the gastrointestinal tract of ruminants. Farm animals such as goats and sheep and wild deer are often a source. Hair is difficult to digest, especially by ruminants. The material can persist in the gut of these animals for months to years. Gradually calcium salts bind to a wad of hair. Peristaltic action, the muscular churning in the GI tract, forces these masses in to the shape of a ball.

The name bezoar is taken from Persian, Padzahr. This word and the concept date to the classical period of Persia, around 500 BCE (Before the Current Era), or over 2000 years ago. The Persian word means “protective against poison” A Persian pharmacopeia of the time listed bezoars as effective in the treatment of not only insect stings and snake bites, they were also considered an antidote to various mineral and vegetable poisons.

By the 16th/17th century their purported efficacy had extended to treating diseases or conditions from epilepsy to smallpox and bubonic plague. Bezoars came to be prized possessions in Europe at the time. For one special use, the stones were encased in ornate gold cage-like containers complete with a several inch long chain attached. These could then be dipped into a goblet of wine for instance, to remove any and all added poisons.

Certain Europeans, Catherine de Medici, and Lucrezia Borgia to name just two were thought to be heartless poisoners who gained and held power by poisoning their political enemies. Poisoning at the time was somewhat of an art. Arsenic was often the poison of choice, and the better poisoners knew how to disguise the poison to make it less detectable.

Interestingly there is a good reason to think that in this particular case of poisoning by Arsenic, the bezoars may have worked to prevent poisoning. Nerd alert – chemistry digression. The physical composition of a bezoar includes hair, and hair is loaded with a class of chemical compounds known as sulfides. The presence of sulfides makes for the foul odor when hair is burned. More importantly however, the sulfides are known to chemically bind to many heavy metals including Arsenic.

For a goblet of wine with Arsenic, adding the bezoar stone could adsorb the poison. Remove the stone and remove the poison.


Chemophobia is a term, often used pejoratively, to describe an unfounded and generally unnecessary fear of “chemicals.” The quotes are necessary because anything with physical substance is a chemical. The phobia is really just a fear of the unknown or the not well understood. Concern should be about the risk of exposure to those that may be toxic, mutagenic, or harmful in in some way, not all chemicals.

After that leap, it makes more sense as different chemicals or mixtures thereof have different potentials for harm, and those potentials are directly related to the dose. Paracelsus (1493-1541), the father of modern toxicology, coined the phrase “everything is toxic, nothing is toxic, the dose makes the poison.” We are bombarded daily by toxic and even carcinogenic substances but the vast bulk of these are present in such small amounts, that the toxic or carcinogenic dose is immeasurable and no harm can be detected.

Historically there are lots of substances which one should rightly fear and lot of them are natural. A class of compounds known as cyanogenic glycosides can release deadly hydrogen cyanide. Lima Beans contain these compounds but at low enough concentration to have no toxic effect whatsoever. Cassava, a annual root crop in tropical parts of the world, also contain cyanide. Generally consumption is not a problem, but when consumed as a significant portion of the diet the cyanide intake can be large enough to cause paralysis in the extremities, blindness and even death. It’s OK to eat tapioca pudding made from cassava just don’t try to live on it.

People are more often fearful of synthetic materials, as if they’re some how automatically toxic regardless how much or how little one is exposed to. Modern chemical analysis can now measure substances down to concentrations unheard of just a decade or two ago. Just because a synthetic compound can be measured in the body doesn’t necessarily mean that it is causing any harm.

Another contributing factor to chemophobia is the “one small study” problem. A small study will show the harmful effect of something, then the press runs with that as a confirmed truth. Often however, small studies are just plain wrong. The beauty of science is that over time we usually get it right. Larger, more well controlled studies can disprove the purported harmful effects.

The Food and Drug Administration was created at a time when there was a clear and present danger to our supply of food and drugs. The scientific consensus is that they currently do a commendable job of protecting us from harm.

Ironically on area of real risk comes from so called natural nutritional supplements. An exception in the law prevents these agents from oversight by the FDA. Whereas most nutritional supplements are harmless (and by the way useless), some have been found to be adulterated with dangerous levels of natural and synthetic compounds. Illness and even death have come from these unregulated agents.