10. Poison gas attacks caused casualties among friendlies during the First World War
The first use of poison gas on the battlefield is usually reported as being in April, 1915, when the Germans fired gas shells at British positions on the Western Front. In fact, the Germans used poison gas against the Russians in January of that year, four months before it appeared in the west. Inexperience with the weapon created problems for the Germans. A failure to consider the shifting winds led to the gas blowing back on German positions, causing problems in several areas of the German lines. The gas used, a form of tear gas called xylyl bromide, froze quickly, rendering it more or less inert, and relatively few casualties suffered on either side. In April, the German Army deployed far more lethal chlorine gas against the British, causing far heavy casualties, and changing modern warfare.
In September 1915, the British responded with poisonous gas attacks of their own. During the opening bombardment preceding infantry assaults at the Battle of Loos, the British released approximately 140 tons of chlorine gas on German positions. British engineers had argued against its use, due to prevailing winds, but the senior officers overruled their recommendations. Deadly chlorine gas blew back over the British troops in the trenches, who suffered a higher rate of casualties from the attack than the Germans. The ineffectiveness of the gas attack also led to higher British casualties once the assault on the entrenched Germans began. Afterward, the British commander who had ordered the gas attack blamed his senior meteorologist for its failure. Other junior officers defended the meteorologist, claiming that he toohad argued against the use of gas, only to be overruled.
