This got me thinking about how long have we been putting chlorine in pools. This random website says that it was "first suggested" in 1894 (without any citation, so take that with a salt water pool's worth of salt).

So shells filled with chlorine gas would not smell like a swimming pool during the US Civil War. Because a swimming pool probably smelled like stagnant water and piss.

[–] this_1_is_mine 7 points 2 weeks ago

To be fair pools still smell like stagnant water and piss... And chlorine. Funny story. If you smell the key pool chlorine smell like someone put way too much in. Guess what it's because the chlorine is reacting with someones mungy piss .