John Wesley Hyatt - was looking for an ivory substitute, particularly for billiard balls. He found an ivory substitute consisting of cellulose nitrate and camphor in 1870, called the product Celluloid and marketed the balls in 1872, with disastrous results - the balls tended to explode when they collided!
Not the first time I'd heard of this phenomena.

Remington used a version they called pyremite for pocket knife scales. Early versions of that stuff were also known to spontaneously ignite.

I bet that made for some interesting games.