That's fascinating I thought as I was slogging through the world wide web earlier today. I happened

upon an article on
The Straight Dope website that explained how lantern mantles used to contain the radioactive material thorium oxide. It's an incandescent material that greatly increases the light output of the lantern when it's heated in the flame. At least until the early 90s Coleman used thorium in their mantles until replacing it with non-radioactive yttrium.
Seems thorium's radioactivity is mostly emitted as alpha particles which we all know don't travel too far from home. But it does explain Uncle Willard's problem with his right testacle which shriveled up like a raisin back in the 70s. Seems back in Willard's woodsman days he used to carry spare mantles in the watch pocket of his Levis.
Also explains why Cousin Cole has six fingers on his left hand.
Man can he play the banjo.