Matt Kaplan

And actually, that's still used in medicine today.

I was going to say, that's actually a good thing.

Yeah, so they were messing around in medicine with these different ideas, and it took years after Galileo before you started having scientists say, well, wait a minute, are leeches actually helping?

There's one guy, he was in France, Pierre-Charles-Alexandre Louis, quite the name, born shortly after the guillotine came down on Louis XVI.

So this is a major time of change in France.

And Louis...

was in this world where people were using leeches, they were holding their finger up and saying, well, you know, the winds aren't quite right, so I think we're going to have disease tomorrow.

Or the stars and the sun aren't in alignment, we think disease is going to happen.

And that's, I mean, that was how science was done in medicine at that time.

And Louis raised the question, are leeches actually helping?

I don't think the leeches are actually doing anything.

And so he said, oh, sacre bleu, I will put on the leeches onto these people on day one of their pneumonia.

My outrageous French accent.

It's terrible.

But he tried an experiment where he put leeches onto patients with pneumonia on day one to try to get the bad blood out of them.

And with the other half of the population, he put leeches on day seven.

Note, he did not treat a control group that had no leeches whatsoever because that would have been heresy.

You weren't allowed to not treat people with leeches back then.

You needed to apply the leeches.

But he found that people who had the leeches on day one were far more likely to die than the people who had the leeches applied quite late.