Chemical warfare during the First World War
After a year of stalemate in Europe, one of Germany’s leading scientist, Fritz Harber, believed he had the weapon to make the breakthrough. His Berlin laboratory had been investigating an asphyxiating gas used in the dye industry - chlorine.
On 22 April 1915, the Germans devastatingly deployed this new chemical weapon. Chlorine gas silently rolled across French and Algerian trenches at Ypres, leaving 10,000 casualties.
However, as the war went on both sides developed more effective gas marks and training. So Fritz Harber’s institute set to work again on a more lethal gas, called mustard gas, which attacked the skin as well as the lungs.