Featured in Episode 09: The Effects of Nothing in The Health Files Podcast
In 1798, Dr. Elisha Perkins noticed something strange during a routine surgical operation. When a metallic instrument was put in direct contact with muscle, he observed a contraction, a sort of spasm. Struck with new and exiting this discovery was, he tried other materials, wood etc., but nothing else gave a similar effect. He tried experimenting with this finding. and realized that in one or two cases, when a knife of other metal surgical instrument was placed in between a tooth and a gum when tooth was about to be pulled - the pain the patient was experiencing mysteriously stopped. How strange, he thought, as his mind put two and two together. Then he remembered a few studies he read about by a physician in Italy.. Galvani, the Italian physicians name, had also found that metal had surprising effects on nerves and muscle fibers. Inspired by this, and his discovery of the connection to blocking pain, Perkins proceeded to make instruments out of various metals.
From his own account, he experimented with designing these instruments for years ardently hoping that further experiments and observations would able him to apply them - the instruments - to the "alleviation of human affliction and the general benefit of mankind". He ended up forming the various metals into a sort of rod, thick and rounded on one end and pointy on the other, sort like a stretched out water drop:
Through his experiments he discovered that he could cure people, just by moving these instruments around on parts of the body that were afflicted with things like chronic pain, inflammation, pain from burns or sprains, swelling and even tumors and fits of epilepsy. He called them "tractors" and patented them as soon as possible.
Quick side note - yes. tractors. I think he took it from traction - meaning the action of drawing of pulling something over a surface, which is probably where the name of the thing you think of when I say tractor comes from as well.
Anyways, with the help of 18th century marketing, the things become a widespread phenomenon in just a few years. The idea was that the metal could draw out noxious electrical fluid that caused the pain and suffering of the patients.
The year after , in 1799, Dr. John Haygarth, a physician in Bath, England decided to put this fad to the test.
"The tractors," he wrote, "have obtained such high reputation at Bath, even among person of rank and understanding as to require the particular attention of physicians. "Let their merit be investigated, in order either to support their fame or, if merely formed on delusion, may the trial correct the public opinion."
He decided to make a series of fake tractors - made of wood, but painted to look exactly the same as the metal ones. He proposed the idea to a colleague, a Dr. Falconer, and together they set up a small clinical trial of sorts, choosing patients fern the general hospital.
They selected 5 patients with chronic rheumatism, basically arthritis. All of the patients joints were swollen and they had been in pain for several months. On the 7th of January 1799 the wooden tractors were used.
The descriptions of the procedure in all accounts I could find are very vague, saying just that the points were drawn over the affected areas touching"the skin in the slightest manner", but I am not sure in what sort of movement or duration.
And here comes the important part: out of the 5 patients, 4 stated that their pain was significantly reduced.
One said his knee was warmer and he could walk much better. Another said the pain was gone for 9 hours, then returned. Another said they had felt a tingling for over two hours in their affected joint. The next say, they repeated the procedure with the same patients, only using the real, metal tractor instruments this time. The patients reported feeling similar effects, but in no greater degree than yesterday.
Haygarth later writes"the whole effect of the tractors undoubtedly depends upon the impression which can be made upon the patients imagination."
His account goes on to describe another 55 pages of his and other physicians similar experiments with different illness and patients, and various effects the patients experienced, each one is more unbelievable than the last.
"What wonderful effects" he says, "the passions of hope and faith, excited by mere imagination, can produce on disease."
Though it doesn't seem like Haygarth actually coined the phrase, but it is exactly this experiment that has been put down in history the first instance of an experiment comparing a real treatment and what later will come to be called...
the placebo effect.
De Craen AJ, Kaptchuk TJ, Tijssen JG, Kleijnen J. Placebos and placebo effects in medicine: historical overview. Journal of the Royal Society of Medicine. 1999;92(10):511-515.
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From the History of Medicine Artifacts Collection: Perkins’s Tractors
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Munana, K. R., D. Zhang, and E. E. Patterson. "Placebo effect in canine epilepsy trials." Journal of veterinary internal medicine 24.1 (2010): 166-170.
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Histories: Elisha Perkins and his medical tractors
Perkins Tractors 1790s
The influence of metallic tractors on the human body, in removing various painful inflammatory diseases, such as rheumatism, pleurisy, some gouty affections: lately discovered by Dr. Perkins, of North America
Of the imagination, as a cause and as a cure of disorders of the body : exemplified by fictitious tractors, and epidemical convulsions ... : read to the Literary and Philosophical Society of Bath
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