This is Side Door, a podcast from the Smithsonian with support from PRX. I'm Lizzie Peabody.

A lot of scientists from the early 1900s were known for being quirky.

Albert Einstein famously did not like to wear socks.

Marie Curie hated public speaking so much.

She almost skipped her own Nobel acceptance ceremony.

Nicola Tesla refused to speak to women wearing pearls and would only stay in hotel rooms divisible by three.

And then there was this guy, Alexander Fleming.

This was a man who could stand and stay at you for an hour without saying a word.

He didn't feel uncomfortable.

You would.

This is Kevin Brown, trust archivist at St. Mary's Hospital in London and curator of the Alexander Fleming Laboratory Museum.

He says Fleming was a bit of an odd duck.

To his colleagues at St. Mary's, he was known as Flem.

Flem was short, wore a bowtie, and smoked three packs a day. And he had an unusual hobby.

He was interested in art. He didn't use oils of watercolors. He did what he called germ paintings. Fleming was a bacteriologist, so he studied

and taught about bacteria for a living. But bacteria often grow in bright colors, which he

liked to use to create artwork, germ paintings.

Basically painting by numbers with books.

And that is why, in the summer of 1928, Fleming went on vacation and left a bunch of petri dishes

sitting out in his lab at St. Mary's Hospital Medical School.

You know, just in case

some grew into cool colors while he was away. And when he returned, at the end of the summer,

...