Gas was a very effective way of attacking the enemy without direct contact. The first use of gas in the war was in 1914, when the French used tear gas grenades against the Germans. This sparked an idea for the Germans, and on 31st of January 1915, they first used Gas on a large scale. Over 18,000 shells filled with gas were launched towards the Russians. This attack failed. Chlorine Gas saw its first use on the 22nd of April 1915 by the Germans against the French. The French thought it was tear gas so took not so much notice of it. As it hit them, they fled in fear and some were overcome with the poisonous gas. A big opportunity had opened up for the Germans. They however had not thought Chlorine Gas had such deadly effects, so retreated, missing a huge opportunity.