The Boy Who Fainted at the Wrong Tree
In 1784, Benjamin Franklin’s commission blindfolded a boy in a Paris garden to test an invisible force. What happened next was real, and the force wasn’t.
A boy hugged an apricot tree, then another, then another, and at the fourth one he fainted.
That happened in 1784, in Benjamin Franklin’s garden at Passy, just outside Paris. The boy was about twelve. He had a padded blindfold over his eyes, and he had been told that one tree in the orchard had been filled with an invisible healing force.
We don’t know his name. The report that describes him never gives it. He shows up in one paragraph, and then he’s gone. Still, that paragraph turned out to matter more than almost anything else in it.
The invisible fluid
The force had a name: animal magnetism. Its champion was Franz Anton Mesmer, a German-born doctor trained in Vienna, who said an invisible fluid ran through the universe and through every living body. Block it and you get sick. A trained healer could get it moving again.
By the early 1780s Paris was full of people who believed him. Patients sat around a wooden tub with iron rods sticking out of the lid, joined by a cord, while music played. Some coughed, laughed, wept or went into convulsions that lasted hours. When one person went into a “crisis,” others tended to follow.
In March 1784, Louis XVI appointed a commission to find out whether the fluid was real. The list included Franklin, the chemist Antoine Lavoisier, the astronomer Jean-Sylvain Bailly and a physician named Joseph-Ignace Guillotin.
Here’s the part most retellings get wrong. They never tested Mesmer. He refused to cooperate. They tested his most prominent follower, a Paris physician named Charles d’Eslon, who agreed to show them everything.
The orchard at Passy
Franklin’s health kept him from travelling into Paris for most of the tests, so some of them came to him.
D’Eslon picked the boy himself, someone he already knew to be sensitive. An apricot tree standing apart from the others was chosen. D’Eslon was led to it alone and magnetized it, while the boy was kept inside the house. D’Eslon insisted on staying to point his cane at the tree, so the commissioners stood between him and the boy.
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Then the boy was brought out and led, blindfolded, to four trees in turn. He hugged each one for two minutes.
At the first, he said he was sweating in large drops. He coughed and had a slight headache. At the second, he felt dazed. At the third, worse, and he said he thought he was getting close. At the fourth, he fainted. His limbs went stiff, and they carried him to the grass.
Not one of those four trees was the magnetized one. The nearest, the one where he collapsed, stood about twenty-four feet from it. He never touched the tree d’Eslon had worked on at all.
D’Eslon had an answer. All trees carry magnetism by nature, he said, and his presence made it stronger. The commissioners pointed out, fairly dryly, that the boy had ridden there in a carriage sitting across from d’Eslon and felt nothing on the way.
What they actually concluded
The report, signed in Paris on 11 August 1784, was blunt. The fluid, it said, has no existence. The effects came from touch, imagination and imitation. One line sums up the whole investigation: imagination without magnetism produces convulsions, and magnetism without imagination produces nothing.
But notice what they didn’t say. They never called the boy a liar. They accepted that the effects were real; they just traced them to the mind instead of to a fluid. A few weeks later, Bailly told the Academy of Sciences that what they had seen were facts for a new science, the influence of the mental on the physical.
Franklin seems to have suspected as much before any test was run. A week after the commission was named, he wrote that he must doubt the thing existed until he could see or feel some effect of it. Then he added a line that’s hard to forget: that delusion may in some cases be of use while it lasts.
Historians of medicine often describe this commission as the first published investigation to deliberately keep its subjects in the dark and use a sham treatment. That idea sits underneath every modern trial of a drug against a sugar pill. To be fair, the idea had older roots, but the commission put it in print, in front of Europe.
The part that never closed
So the fluid was never real. The boy’s collapse was. He sweated, ached, stiffened and fell because of what he expected, in a garden where nothing had been done to him.
I keep coming back to how little we know about him. A whole field of medicine leans on one paragraph about a boy whose name nobody wrote down. Whether he ever learned what that afternoon proved, we can’t say.
If an idea placed in your head by the right people, in the right setting, can knock you off your feet, it’s worth asking which trees you’ve been led to lately.
Final Vestige Studios publishes short stories about forgotten knowledge and the mysteries that never quite closed.
