I always thought the Confederates fought in a most civilized manner. Despite their desperation and ultimate defeat, they treated the enemy prisoners as well as possible and there are no mass graves of their black population. Indeed, the only wartime mass grave of the black population I am aware of is in New York City where the ancestors of today's "snow flakes" slaughtered them to demonstrate their opposition to the draft. But I digress.
While browsing the tens of thousands of CS documents available on fold3.com, I find the naughty Rebel ordnance boys came up with a "suffocating shell." It was developed in Nashville at the same time Forts Henry and Donelson were being captured by Gen. Grant. An appropriately named "Professor Vile" was responsible and presented his concept to Col. Gorgas, the Chief of Ordnance in Richmond. Gorgas ordered five samples to be sent to Richmond. They were produced in February 1862 by Nashville's Ellis & Moore, one of the primary western theater suppliers of artillery projectiles until the city fell a short time later. The invoice is pictured below reading: "5 Suffocating Shells fitted up for Prof. Vile forwarded to Col. Gorgas." They were large mortar balls obviously intended to hinder the North's powerful river fleet. The last document pictured below is a letter to Capt. Moses Wright, commander of the Nashville Arsenal, soon to gain fame as commander of the Atlanta Arsenal. "I will be much obliged if you will let the bearer have an order for me to take ___ mortar shells to the Penitentuary and fill them immediately in order to send away to Richmond by request of Col. Gorgas... I am going to fill them with explosives, etc., leaving out the poison..." I don't even want to know what the penitentuary was doing with "Suffocating Gas" on the premises.
Woodenhead