Chrissy,
My reference list is definitely incomplete. I am sure that there are many more mentions of shells.

Here is one more:
Cooper, John Spencer (sergeant, 7th Fusiliers), Rough Notes of Seven Campaigns in Portugal, Spain, France, and America, During the Years 1809-10-11-12-13-14-15, London, 1869, p. 84-85: French shells at the battle of Vitoria.