Ammo Solid shot or shell

[Carronade]

In Napoleonic times, "case shot" was similar to canister; some sources characterize it as an alternative term for canister. Either way it was like a large shotgun load, firing a blast of balls directly from the mouth of a cannon, effective at close range.

Shells of course were hollow iron spheres filled with gunpowder, fused to explode at a set time/distance.

As @Rhea Cole mentioned, Henry Shrapnel's innovation was to include small balls inside a shell which would explode over or among enemy troops, giving an effect similar to case shot, hence his term "spherical case".