Trial by GasWorld War I has long captured the macabre imagination for the seemingly willful manner in which nations sent their young men to die in droves while fighting over essentially the same patch of land for four long years. The vision of those senseless deaths becomes even harsher and more depraved when we consider how many soldiers were killed by poison gas. In May 1915 the long and bloody Second Battle of Ypres gained notoriety for the participants use of