The Germans were not the first to employ gas during the First World War. Technically the French experimented with a form of tear gas which was not considered to be in violation of the Hague Treaty.
The Germans, like the French, experimented with mild forms of riot gas, but they had not the desired result. The German High Command enlisted the help of Nobel Prize Winner, Fritz Haber, pictured on the right with Albert Einstein. Haber was influential in Germany's war plans because not only did he devise plans for the mass release of chlorine from cylinders, but he also devised a process to convert nitrogen and hydrogen gases, from the atmosphere, into ammonia. Ammonia was later used to make explosive.

Haber's plan to release chlorine was adopted at Ypres in April 22, 1915.

Not only is ammonia used to make explosive mixtures but it is also used to make fertilisers. His discovery started the agricultural revolution where the output per acre increased a hundredfold. Nations could now feed their people without a heavy reliance on imported fertilisers. It was for this reason that in 1911 Haber won the Nobel Prize in Chemistry.

The supply of nitrates was running desperately short as a British naval blockade had cut off supplies of nitrates from Chile. In 1914 a concerned German High Command enlisted Haber to produce guncotton that did not require sodium nitrate for its production.