The soldiers are part of the Russian Fifth Army of World War One. They are preparing a chemical attack against the German positions in Ilukste area (modern Latvia). Chlorine was first introduced in the battlefield by the German Army in 1915. As described by the soldiers it had a distinctive smell of a mixture between pepper and pineapple. It also tasted metallic and stung the back of the throat and chest. Chlorine can react with water in the mucosa of the lungs to form hydrochloric acid, an irritant that can be lethal.
The damage done by chlorine gas can be prevented by the activated charcoal commonly found in gas masks, or other filtration methods, which makes the overall chance of death by chlorine gas much lower than those of other chemical weapons. Chlorine gas was pioneered by a German scientist later to be a Nobel laureate, Fritz Haber of the Kaiser Wilhelm Institute in Berlin, in collaboration with the German chemical conglomerate IG Farben, who developed methods for discharging chlorine gas against an entrenched enemy.
How the gas was delivered to the enemy positions? The first system employed for the mass delivery of gas involved releasing the gas cylinders in a favorable wind such that it was carried over the enemy’s trenches. The main advantage of this method was that it was relatively simple and, in suitable atmospheric conditions, produced a concentrated cloud capable of overwhelming the gas mask defenses. The disadvantages of cylinder releases were numerous. First and foremost, delivery was at the mercy of the wind. If the wind was fickle, as was the case at Loos, the gas could backfire, causing friendly casualties. Gas clouds gave plenty of warning, allowing the enemy time to protect themselves, though many soldiers found the sight of a creeping gas cloud unnerving. Also gas clouds had limited penetration, only capable of affecting the front-line trenches before dissipating. Finally, the cylinders had to be emplaced at the very front of the trench system so that the gas was released directly over no man’s land. This meant that the cylinders had to be manhandled through communication trenches, often clogged and sodden, and stored at the front where there was always the risk that cylinders would be prematurely breached during a bombardment.
- It is alleged that Haber’s role (the inventor) in the use of chlorine as a deadly weapon drove his wife, Clara Immerwahr, to suicide.
- The contribution of gas weapons to the total casualty figures of WW1 was relatively minor. British figures, which were accurately maintained from 1916, recorded that only 3% of gas casualties were fatal, 2% were permanently invalid and 70% were fit for duty again within six weeks.