Perkins' Metallic Tractors: Doctors Used To Think These Metal Rods Could Cure Everything

This article forms part of the IFLScience exciting editorial calendar for 2023.

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology

Dr. Russell Moul

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology

Dr. Russell Moul

Science Writer

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology.

Science Writer

Caricature of a quack treating a patient with Perkins Patent Tractors

Perkin's Metallic Tractors were widely sought after. 

Image credit: Wellcome Images via Wikimedia Commons (CC BY 4.0)

The history of medicine is full of dubious claims and outlandish ideas. We have all heard of quack practitioners who claim medical expertise in order to promote and sell nonsense treatments and nostrums. These individuals experience various levels of success, but usually, their bogus claims are discovered before too long. But what about instances where medical professionals genuinely believe a treatment or therapy is real?

In 1796, Elisha Perkins, a physician in Connecticut, started selling an unusual device – two stretched tear-drop-shaped metal rods, one made of iron and the other brass – which he claimed produced miraculous healing effects. According to Perkins, simply touching these so-called “Tractors” to your skin could potentially cure a range of ailments, including inflammation, epilepsy, and rheumatism.


The Perkins’ Metallic Tractors, as they became known, were sold as a pair (for 25 Continental dollars in the US and 5 guineas in Britain) and could be used by anyone. This was part of their appeal. Not only were they promoted as a simple cure-all device, you didn’t even need to be a doctor to use them – as long as you could apply them to the injured or painful area then you were ready to go.

Perkins learned his medical trade from his father, Joseph Perkins, who graduated from Yale College in 1727 and established a practice in Norwich, Connecticut. It was here that Elisha gained his medical knowledge as an assistant before he moved to Plainfield, Connecticut, where he started his own practice and created a medical academy. He became the Chairman of the Windham County Medical Association in 1795, and also was selected as a delegate to the Connecticut Medical Society. In short, Perkins looked to be a star on the rise who would have a successful medical career ahead of him. That is until his “discovery” of the Tractors eventually turned him into a renowned quack. But this is not a tale of a charlatan waiting to be discovered.

The rising physician first became aware of the phenomenon he would eventually patent while performing a surgical operation where he noted how a muscle would contract whenever he touched it with the point of a metallic instrument. He then experimented with other materials, such as wood, and found that only metal objects elicited the perplexing result.

Apparently, around the time he was poking people with different instruments, Perkins also noted how, when cutting gums with a metal knife ahead of a tooth extraction, the patient seemed to experience a lessening of pain. He also observed a similar response when applying metallic instruments to inflamed tumors before he cut into them. As a good empiricist, Perkins then experimented with different metals to see which worked best and eventually settled on a combination of two rods, one of brass and one of iron.

Perkins’ Metallic Tractors
Perkins’ Metallic Tractors
Image credit: Geni via Wikimedia Commons (CC BY-SA 4.0)

Initially, the Tractors were met by ambivalence and hostility within some medical circles, especially among those who were already suspicious of claims made by contemporary proponents of Animal Magnetism. But for many more people and doctors in America and Europe, his patented rods were a sensation.

He and his son set off on a successful promotional tour in 1796 and published various pamphlets celebrating the discovery and the Tractor’s efficacy. Positive testimonies from high-profile doctors and public officials, including George Washington who had allegedly bought a pair of Tractors for his family, quickly bolstered their credibility. They became so successful, in fact, that they became a currency of exchange in themselves – people even used property, horses, and carriages to pay for certain numbers of Tractors.

Despite the public enthusiasm for the Perkins’ Metallic Tractors, skepticism remained. In 1797, the Connecticut Medical Society expelled Perkins from their number on the grounds that he was a quack, while others sought to understand what made the Tractors work in the first place.

Experiments were performed with metal instruments and magnets to see if they would produce the same outcome – which they did – while, in 1800, an English physician attempted to test the “fictitious tractors” by using two wooden rods disguised as metal. John Haygarth, a physician in Bath, England, found that he could produce the same effects with these fake objects. He concluded that the “whole effect undoubtedly depends upon the impression which can be made upon the patient’s imagination.”


Today, we would regard this as one of the earliest experiments to demonstrate the placebo effect, but it was just one of the many tests conducted by physicians to debunk the hype behind the Tractors. Anything, it seemed, could be used to produce the same effects Perkins claimed as his own, just as long as the patient believed they were being treated with official Perkins’ Tractors.

After this, Perkins’ Tractors became a source of ridicule. They were lambasted by cartoons and in newspapers and eventually, the rods fell from fashion. But despite this, they still enjoyed commercial popularity for some time after Perkins’ death in 1799.

While it might be tempting to regard Perkins as a simple quack, that is not really accurate or fair. Not only did he generate his ideas in good therapeutic faith, but they were also enthusiastically greeted by many of his medical peers. Instead, his story tells us lots about how medical ideas can sometimes generate their own mythology and that history is filled with ideas that seem too good to be true until they are proven to be just that.

To read more fascinating stories, check out our free Common Medical Myths And Misunderstandings eBook. 


All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.


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  • placebo,

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  • History of medicine,

  • metal,

  • myth,

  • myth busting