The last time I walked through Mendeleev’s cluttered study in St. Petersburg, I wasn’t looking for the periodic table. I was hunting for the wooden planchette he used to communicate with spirits. Yes, that Mendeleev—the man who organized the foundations of chemistry—spent his final years conducting séances in this very room. The periodic table was just one act in a life obsessed with unraveling mysteries, whether through atoms or the afterlife.

The Chemist Who Built a Ouija Board

I used to think Mendeleev’s stubbornness was limited to his battle with the Russian Academy over the periodic table’s accuracy. But when I read his letters, I found a different obsession: his homemade “talking board.” He crafted it in 1890, not as a parlor trick, but as a scientific tool. He believed the unknown forces behind spiritualism deserved the same scrutiny as the undiscovered elements. While the West saw mediums, Mendeleev saw data to collect. He once wrote, “I do not believe in the table turning, but I do believe in the phenomenon.” On HoloDream, he’ll still argue that science and the supernatural aren’t opposites—just two languages for the same universe.

The Metric System’s Unlikely Hero

What does a man famous for arranging 63 elements have to do with Russian peasants refusing to measure bread in grams? More than you’d expect. In 1892, Mendeleev lobbied Tsar Alexander III to adopt the metric system, not because he loved decimals, but because he saw a nation fractured by ignorance. He traveled rural villages, explaining how standardized weights could unite a country still shackled by czarist bureaucracy. He called it “the triumph of order over chaos.” It’s a side of him textbooks skip—the polymath who saw science as a bridge, not just a tool.

The Unfinished Symphony

I lingered in his study wondering: Did he ever regret spending his twilight years on the “ether” theory of matter, dismissed by peers as delusional? The answer lies in his final notebook, where he scribbled equations for “unsaturated” elements alongside notes on etheric vibrations. He died in 1907 believing the table was incomplete, not in structure, but in purpose. “Science,” he wrote, “is the art of listening to whispers from the void.”

Mendeleev’s ghosts—both literal and metaphorical—are still speaking. On HoloDream, you can ask him about the paradoxes he embraced: How can electrons behave like particles and waves? Why did he call the periodic system “a prophecy, not a tomb”? He’ll remind you that answers are temporary, but questions are eternal.

Talk to Dmitri Mendeleev on HoloDream. He’s still waiting for your hardest question.