Yesterday marked a grim anniversary. The BBC reports:
As he climbed to the top of the church belfry in Bolimow, west of Warsaw, General Max Hoffman of Germany's Ninth Army was expecting a bird's-eye view of a military breakthrough - and a new chapter in warfare.
The date was 31 January 1915, and he was about to witness the first major gas attack in history.
Gen Hoffman watched as 18,000 gas shells rained down on the Russian lines, each one filled with the chemical xylyl bromide, an early form of tear gas. But the results left him disappointed.
"I had expected much greater results from the employment of this ammunition in - as we then imagined - such large quantities. That the chief effect of the gas was destroyed by great cold was not known at that time."
But the failure at Bolimow proved to be only a temporary setback.
By April, German chemists had tested a method of releasing chlorine gas from pressurised cylinders and thousands of French Algerian troops were smothered in a ghostly green cloud of chlorine at the second Battle of Ypres. With no protection, many died from the agonies of suffocation.
Within a few days, the Daily Mail published an editorial lambasting "the cold-blooded deployment of every device of modern science" by the Germans.
The commander of the British Expeditionary Force, Sir John French, called the use of gas "a cynical and barbarous disregard of the well-known usages of civilised war".
But four months later Britain itself attacked the German trenches with gas, at the Battle of Loos.
"Owing to the repeated use by the enemy of asphyxiating gases in their attacks on our positions, I have been compelled to resort to similar methods," Sir John explained.
. . .
The standard-issue gas mask in 1917 - the "small box respirator" - provided good protection against chlorine and phosgene.
But soon all sides had turned to gases which maimed even soldiers wearing a mask - blistering agents, or "vesicants".
The most widely used, mustard gas, could kill by blistering the lungs and throat if inhaled in large quantities. Its effect on masked soldiers, however, was to produce terrible blisters all over the body as it soaked into their woollen uniforms. Contaminated uniforms had to be stripped off as fast as possible and washed - not exactly easy for men under attack on the front line.
. . .
Other terrible weapons were developed at the same time. The flamethrower appear on the Western Front in 1915, two months before gas. Other weapons, like the machine gun, were honed to new levels of murderous perfection. The biggest killer of all was artillery. Yet it was only the use of all gas that was outlawed by the Geneva Protocol of 1925.
There's more at the link. Wikipedia also has a good overview of the topic.
Germany would go on to use poison gas to terrible effect in the extermination camps of World War II. The Allies produced large quantities of poison gas during that conflict in order to retaliate against possible enemy use of the weapon, but tragically scored an 'own goal' with it when a ship carrying a large quantity of mustard gas was bombed by German aircraft in Bari harbor, Italy, in December 1943, releasing its cargo. Thousands of Allied sailors and servicemen and Italian civilians were affected.