Most of us are probably at least vaguely familiar with the story of Frankenstein. It’s a cornerstone of pop culture, especially in the more monstrous circles. But what most of us probably don’t know is that Mary Shelley based her fictional novel on some very real experiments of her time.

Isn’t Frankenstein just some monster?

Maybe a quick review of the original book would help, since there have been so many different versions of the story across the years. The original protagonist, Dr. Frankenstein, gathered pieces of corpses and sewed them together, eventually running an electrical current through them and bringing his creation to life.

Pixabay / Sirenia57

The creature could think, and eventually learned to speak, just like any other human. This story is already fairly creepy, but the real-life experiments going on at the time were just as creepy.

What, exactly, were scientists doing?

For about a century before Mary Shelley ever touched pen to paper, scientists had been toying with the idea that electricity could have some special relationship to life itself. Even Sir Isaac Newton thought as such. One French scientist once made nearly 200 royal guards jump simultaneously by running an electrical current through their bodies.

Unsplash / Hal Gatewood

But scientists also experimented on some less-than-lively test subjects.

Bringing them back from the dead

Many scientists of the 1800s started experimenting with dead bodies by running electrical charges through them. Witnesses were often horrified at the events, watching as the muscles of the corpses twitched and moved, and the faces of the dead persons often convulsed into terrifying expressions.

Flickr / Marian Parsons

None of the corpses were brought back to life—but by the time Mary Shelley wrote Frankenstein, pretty much everyone had heard of the concept, making her book that much more interesting to the general population. Electricity may have turned out not to be the secret link to life, but it could still do some pretty crazy stuff.