Skip to main content

Newton's recipe for 'toad vomit lozenges' up for auction

This cane toad would rather not be part of a plague treatment.
This cane toad would rather not be part of a plague treatment. (Image credit: Shutterstock)

Sir Isaac Newton — famous for developing the three laws of motion and advancing calculus — apparently had a far-out idea for how to treat the plague, also called the black death: toad-vomit lozenges.

In addition to recommending a number of gemstone amulets against the plague, he gave detailed instructions on how to make the putrid toad-vomit treatment, according to two unpublished pages handwritten by Newton that are now on the auction block.

Newton describes in detail how to suspend a toad by its legs in a chimney for three days, until it vomits up "earth with various insects in it." This vomit must be caught on "a dish of yellow wax," he added.

Related: Equal & opposite reactions: Newton's third law of motion

After the toad dies, its body should be turned into powder, mixed with the vomit and a serum and "made into lozenges and worn about the affected area." This treatment would drive "away the contagion" and draw "out the poison," Newton wrote.

The toad treatment was best, but if someone was in a pinch, then amulets made out of the gemstones hyacinth, sapphire or amber could also serve as antidotes, he wrote. 

This two-page document, with Isaac Newton's "frog vomit" recipe, it up for auction.

This two-page document, with Isaac Newton's "frog vomit" recipe, it up for auction.  (Image credit: Bonhams)

Newton and his contemporaries didn't know that the plague doesn't respond to toad vomit or gems. It wasn't until 1894 that the French-Swiss scientist Alexandre Yersin learned that the disease is caused by a bacterium, which was later named Yersinia pestis in his honor.

These days, plague is treated with antibiotics, not vomit from toads that were hung upside down. (On a somewhat related note, if you want to see a toad throw up, here's a video.)

Newton likely wrote these notes on the plague shortly after returning to the University of Cambridge in England in 1667, according to Bonhams, the auction house selling off the documents. The plague had just swept through Europe, forcing the University of Cambridge to temporarily close its doors in 1665. During that time, Newton quarantined at Woolsthorpe-by-Colsterworth, a hamlet in Lincolnshire, England, where he investigated the laws of gravity and motion. The year 1666 became known as his "annus mirabilis," Latin for "wonderful year."

Sir Isaac Newton

Sir Isaac Newton (Image credit: Bonhams)

However, while the polymath's laws of motion became blockbusters, his writings on the plague's causes, symptoms and treatments did not enjoy world renown. In truth, these notes weren't entirely his own. Rather, Newton had been reading "Tumulus Pestis" ("The Tomb of the Plague"), by Jan Baptist Van Helmont, a chemist, physiologist and physician from the Spanish Netherlands, a collection of Holy Roman Empire states also run by the Spanish Crown.

"Newton's notes are not verbatim transcriptions of Van Helmont's text, but rather a synthesis of his central ideas and observations through Newton's eyes," according to Bonhams.

Not everything Van Helmont wrote was dismissed by later generations. For instance, he found that chemical reactions could produce substances that were neither solids nor liquids, which led him to invent the word "gas," according to the Science History Institute in Philadelphia. But religious zeal led to some unusual medical treatments. A verse in the King James Bible at time proclaimed  "the Lord created medicines from the earth, and a sensible man will not despise them," (Ecclesiasticus 38:4). Van Helmont interpreted this line to mean that doctors were ordained by God, and spent the rest of his life convincing others that this was his role, according to the Science History Institute. 

In 1936, Newton's "plague" manuscript was sold along with  a vast trove of his other writings in   Sotheby's Portsmouth sale, but these two pages were uncovered only recently after being lost for more than 70 years, according to Bonhams. Bidding is currently at $65,000 and goes until June 10.

Originally published on Live Science.

OFFER: Save 45% on 'How It Works' 'All About Space' and 'All About History'!

For a limited time, you can take out a digital subscription to any of our best-selling science magazines for just $2.38 per month, or 45% off the standard price for the first three months.View Deal

Laura Geggel
As an associate editor for Live Science, Laura Geggel covers general science, including the environment, archaeology and amazing animals. She has written for The New York Times, Scholastic, Popular Science and Spectrum, a site covering autism research. Laura grew up in Seattle and studied English literature and psychology at Washington University in St. Louis before completing her graduate degree in science writing at NYU. When not writing, you'll find Laura playing Ultimate Frisbee.