Arsenical brass

Okay kiddo, have you ever heard of brass? It's a metal that's made by mixing copper and zinc together. But sometimes, people add a little bit of something called arsenic to the mixture, which makes the metal stronger and more durable.

However, arsenic is a very toxic substance, which means it can make people very sick if they touch it or breathe it in. That's why we don't really use arsenical brass anymore.

So, to summarize: brass is a metal made from copper and zinc, but sometimes people used to add arsenic to make it stronger, even though arsenic is not safe for people.