While researching the Third Michigan Battery, I came across a letter written by of one of the soldiers of the Battery in which he mentions another cannoneer who had been shot in the upper arm by a Rebel musket ball,during the Battle of Corinth, MS.(Oct.4, '62) and who subsequently lost it by amputation. The author wrote that "the ball was poisoned", of course this was conjecture on the part of the author, but there must have been a rumour that the Rebels were using "Poisoned bullets"