Secret experiments by a 16th-century alchemist involved an element that nobody knew about at the time

• Tycho Brahe, an astronomer, studied alchemy to help make medical elixirs.
• Researchers found traces of tungsten in shards of glass and ceramic from his laboratory.
• Tungsten wouldn't be isolated for nearly 200 more years, making it an unknown element at the time.

One of history's leading 16th-century astronomers, Tycho Brahe, was also an alchemist who kept the secrets of that pursuit under wraps.

Researchers previously found that Brahe regularly consumed gold and wanted to learn more about the kind of chemical substances he used in his laboratory, which was located on what's now the Swedish island of Ven.

So, they examined shards of glass and ceramic collected from the lab's remains to see which elements and chemical elixirs Brahe was mixing up.

Many of the elements they found were what any alchemist would have on hand. But the presence of tungsten was extremely puzzling, the researchers reported in a paper published in the peer-reviewed journal Heritage Science.

How and why tungsten — a shiny, silvery-white metal — came into Brahe's possession "is quite a mystery," Kaare Lund Rasmussen, who led the research, told Business Insider via email.

The element wasn't isolated until nearly 200 years later.

"It's the first time we've had any kind of indication that any alchemist was working with tungsten," Lawrence Principe, a professor at Johns Hopkins University who was not involved in the research, told BI.

The secret recipes of alchemists

Not all alchemists were trying to transmute metals into gold. Brahe, for example, was mainly concerned with its medical applications.

He had a trio of medicines for treating plague, scabies, and other diseases, but — like many alchemists of his time — Brahe mostly kept his recipes and research secret.

After his death, Brahe's elaborate laboratory and observatory was destroyed, taking many of its secrets with it. However, excavators salvaged pieces of glass and ceramic from the garden in the 1980s and early '90s, which is still helping researchers today.

Rasmussen and colleagues recently analyzed the shards for evidence of 31 trace elements to determine which Brahe may have used in his laboratory.

Some of the elements the researchers found, like copper, gold, and mercury, were referenced in Brahe's medical recipes, but Rasmussen said it's impossible to know if that's how he used them.

In addition to medical experiments, Brahe could have been trying to uncover the secrets of other minerals. Anything containing tungsten would have likely fascinated him because of its weight.

When you pick it up, "you immediately realize you've got something unusual in your hand because it's so heavy," Principe said. It would have been easy to mistake it for another dense, heavy element: gold.

The endless search for better medicine

What Brahe thought of the tungsten in his possession — if he even realized its uniqueness at all — may never be known.

But Principe, who's been studying alchemists for decades, thinks these newer techniques for analyzing remnants from their laboratories offer incredible insight it what was once a highly secretive discipline.

"That's really giving us, as you could say, sort of firsthand knowledge" of alchemists' work, he said, adding, "It's giving us a lot more information to go on."

Though alchemists' elixirs were a far cry from the scientific rigor and effectiveness of today's medicines, Principe said the hoped-for outcome was the same.

"We're always looking for some kind of better medicine," he said, "something that will extend life or make one healthier or stronger."

Rasmussen said they only tested a small number of samples and hope to analyze more shards to better understand exactly what Brahe was studying with his secret experiments and what he may have discovered.