An antique "Arbaleste à grenade", this is a startlingly old means of launching a grenade, in this case a glass sphere with two chambers containing chemicals. The effect is that once the sphere hits a hard surface, it breaks and the reagents mix, causing an unknown reaction.
They were not particularly effective, fairly cumbersome and require to hit a hard surface to even work. Still, they are a relic of a bygone age where ingenuity was not yet dead.
