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Toadstone

Toadstone is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Toadstone rather than just read about it. In short: The toadstone, also known as bufonite (from Latin bufo, "toad") and crapaud-stone, is a fossil gem that was once believed to be found in the heads of toads, and ascribed magical powers. It was supposed to be an antidote to poison and in this it is like batrachite, supposedly formed in the heads of frogs.

Toadstone — main illustration
Toadstone — illustration

Key takeaways

  • Toadstone belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Toadstone to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Toadstone from memory before moving on to harder problems.

Reference excerpt

The toadstone, also known as bufonite (from Latin bufo, "toad") and crapaud-stone, is a fossil gem that was once believed to be found in the heads of toads, and ascribed magical powers. It was supposed to be an antidote to poison and in this it is like batrachite, supposedly formed in the heads of frogs. Toadstones were actually the button-like fossilised teeth of Scheenstia (previously Lepidotes), an extinct genus of ray-finned fish from the Jurassic and Cretaceous periods. They appeared to be "stones that are perfect in form" and were set by European jewellers into magical rings and amulets from Medieval times until the 18th century.

Beliefs

From ancient times people associated the fossils with jewels that were set inside the heads of toads. The toad has poison glands in its skin, so it was naturally assumed that they carried their own antidote and that this took the form of a magical stone. They were first recorded by Pliny the Elder in the first century. Like the fossilised shark teeth known as tonguestones, toadstones were thought to be antidotes for poison and were also used to treat epilepsy. As early as the 14th century, people began to adorn jewelry with toadstones for their magical abilities. In their folklore, a toadstone was required to be removed from an old toad while the creature was still alive. 17th century naturalist Edward Topsell wrote that this could be done by setting the toad on a piece of red cloth. The true toadstone was taken by contemporary jewellers to be no bigger than the nail of a hand and they varied in colour from a whitish brown through green to black, depending on where they were buried. They were supposedly most effective against poison when worn against the skin, on which occasion they were thought to heat up, sweat and change colour. If a person were bitten by a venomous creature a toadstone would be touched against the affected part to effect a cure. Alternatively Johannes de Cuba, in his book Gart der Gesundheit of 1485, claimed that toadstone would help with kidney disease and earthly happiness. Loose toadstones were discovered among other gemstones in the Elizabethan Cheapside Hoard and there are surviving toadstone rings in the Ashmolean Museum and the British Museum.

Allusions in literature The toadstone is alluded to by Duke Senior in Shakespeare's As You Like It (1599), in Act 2, Scene 1, lines 12 to 14:

In James Branch Cabell's short story "Balthazar's Daughter" (collected in The Certain Hour) and its subsequent play adaptation The Jewel Merchants, Alessandro de Medici attempts to seduce Graciosa by listing various precious jewels in his possession, including "jewels cut from the brain of a toad". In the fifth book of Emily Rodda's fantasy series Deltora Quest, the protagonists must retrieve a magical jewel set in the head of a giant toad.

Jewelry

Some toadstones were used in jewelry, including on a crown held at Aachen Cathedral used to coronet Charles IV, Holy Roman Emperor.

See also Bezoar Biomineralization

References

Further reading New Oxford American Dictionary, under the entry "toadstone". The Complete Works of William Shakespeare by Crown Publishers Inc

External links

"Toadstones: A Note to Pseudodoxia Epidemica, Book III, chapter 13" A collection of notes maintained by James Eason of the University of Chicago comprising excerpts from Thomas Nicols and other authors New York Times reference, 5 October 1890 Whitehurst, John (1713–1788). An Inquiry into the Original State and Formation of the Earth, pp. 184–5, 190 and ff).

Illustrations

Toadstone: Collection of a Toadstone, illustrated in Hortus Sanitatis, published in Mainz in 1491.
Collection of a Toadstone, illustrated in Hortus Sanitatis, published in Mainz in 1491.
Toadstone: Lower jaw fragment of Scheenstia, showing the teeth in situ
Lower jaw fragment of Scheenstia, showing the teeth in situ
Toadstone: Toadstones from Jurassic sediments in Oxfordshire, England
Toadstones from Jurassic sediments in Oxfordshire, England
Toadstone: Silver toadstone ring of the fifteenth–sixteenth century
Silver toadstone ring of the fifteenth–sixteenth century

Worked examples

Example 1 — a first encounter with Toadstone

Start with the simplest possible case. Write down what Toadstone claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Toadstone before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Toadstone ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Toadstone

In research
Toadstone appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Toadstone in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Toadstone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Folklore, Fossils, Lepisosteiformes, so understanding it makes those chapters shorter.
In everyday life
Look for Toadstone outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Toadstone in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Toadstone means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Toadstone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Toadstone in simple terms?

The toadstone, also known as bufonite (from Latin bufo, "toad") and crapaud-stone, is a fossil gem that was once believed to be found in the heads of toads, and ascribed magical powers. It was supposed to be an antidote to poison and in this it is like batrachite, supposedly formed in the heads of…

Why does Toadstone matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Toadstone?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Toadstone.

Tags

  • Folklore
  • Fossils
  • Lepisosteiformes
  • Magic items
  • Mythological substances
  • Toads in culture

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