Bezoar

A bezoar or enterolith is a sort of calculus or concretion, a stone found in the intestines of mostly ruminant animals. There are several varieties of bezoar, some of which have inorganic constituents and others organic.

Bezoars were formerly sought after because they were believed to have the power of a universal antidote against any poison. It was believed that a drinking glass which contained a bezoar set within would neutralize any poison poured into the glass. The word "bezoar" ultimately comes from the Persian pâdzahr (پادزهر), which literally means "protection from poison." In fact, some types of trichobezoar are apparently able to precipitate or bind arsenic compounds (long used as poison) from a solution.

A famous case in the common law of England (Chandelor v. Lopus, 79 Eng Rep. 3, Cro. Jac. 4, Eng. Ct. Exch. 1603) announced the rule of caveat emptor, "let the buyer beware" if the goods he purchased are in fact genuine and effective, in a case over a purchaser who sued for the return of the purchase price of an allegedly fraudulent bezoar. (How the plaintiff discovered that the bezoar did not work is unfortunately not discussed in the report.) Judicial scepticism over the alleged magical powers of bezoars may well have justified this judgment in this particular case. The ruling, however, was seized on and formed an impediment to the formation of effective consumer protection remedies and the law of implied warranty well into the nineteenth century.

Bezoar pearls
In addition to bivalve pearls, there are a group of sacred natural gemstones largely considered bezoar stones, which were first documented in the Garuda Purana, one of the books of Hindu holy text Atharvaveda.

In addition to oyster pearls, also enumerated are the Conch Pearl, Cobra Pearl, Boar Pearl, Elephant Pearl, Bamboo Pearl, Whale Pearl, Fish Pearl, and Cloud Pearl. These pearls were later documented in the treatise Brihat-Samhita ("The Great Compilation") of Varahamihira, the Indian mathematician. The first documented contact with these artifacts by the Western world is described in the sole volume of 18th Century scientist Albertus Seba, entitled Cabinet of Natural Curiosities. Therein, a large collection of bezoar stones and non-oyster pearls were hand-sketched, and the collection of these items were on display in a forum which was the precursor of the modern day museum. Today, the original 446-plate volume, part of the greater work Locupletissimi Rerum Naturalium Thesauri Accurata Descriptio, is on permanent exhibit at the Koninklijke Bibliotheek in The Hague, Netherlands.

While the sacred Nine Pearls of Vedic tradition are typically considered bezoars, the Bamboo Pearl forms in the stem of the Bamboo plant, while others such as the Cloud Pearl have no known formation process.

Types of bezoars

 * A trichobezoar is a bezoar formed from hair - an extreme form of hairball. Humans who frequently consume hair sometimes require them to be removed.
 * Phytobezoars are composed of nondigestible food material by humans (e.g., cellulose) and is frequently reported in patients with impaired digestion and decreased gastric motility.
 * Pharmacobezoars (or medication bezoars) are mostly tablets or semi-liquid masses of drugs.

Miscellaneous

 * Other types of bezoars are formed from items such as stone or sand, usually in young children.
 * Ox bezoars are used in Chinese herbology, where they are called Niu-huang.
 * In alchemy, animal bezoar is the heart and lungs of the viper, pulverized together.
 * In alchemy, mineral bezoar is an emetic powder of antimony, correct with spirit of nitre, and softened by repeated lotions, which were said to carry off the purgative virtue of the antimony, and substitute a diaphoretic one. It promoted sweat like the stone of the same name.

In popular culture

 * Bezoars were featured in the Sandman comic storyline Calliope, in the graphic novel The Sandman: Dream Country.
 * Bezoars have made appearances in fiction ranging from Robert Jordan's Further Chronicles of Conan to the more recent Harry Potter series by J.K. Rowling in which it is used as a cure for poison.
 * A Darwin Award was awarded to someone who died from a bezoar resulting from compulsively eating her own hair.