Given the development of firearms and the few alternatives to advance in the face of their greater reach, the First World War became a trench warfare. Along with the development of conventional weapons, chemical weapons (tear gas, mustard gas and phosgene) also did so in this conflict. The only alternative to those new ways of killing and, above all, of causing chaos and fear, was the use of gas masks. Given the impossibility of wearing them all the time, several animals were investigated to use them as "confirmation devices for toxic gases or chemical agents ” (just like the chickens in the Gulf War), but none of them worked…until Paul Bartsch stepped in. , university professor and curator at the US National Museum of Natural History.
Parallel to the work and research that he carried out at the University and at the Museum, Paul Bartsch continued to investigate at home in other fields that were not so academic but equally fruitful. Although the line of research was another, in one of these home works that he developed with garden slugs (Limax maximus ), he found that they reacted to the smoke emitted by the boiler in his house. He focused on this line of work and after several experiments he came to the conclusion that slugs were the device the army was looking for…
Human beings are able to detect mustard gas when the concentration of mustard gas particles in the air is 1/4,000,000, and it is usually too late to put on the mask. However, the slugs detect the presence of this gas when the gas/air ratio is 1/12,000,000, giving more than enough time for soldiers to don their masks. In addition to their extraordinary sense of smell to detect them, they have the ability to shut down their respiratory system and protect their lungs from harmful gases, so they can serve for more than one “use ”.
When he had finished his work, he brought it to the attention of the US Army. Its proven effectiveness and the tremendous ease of carrying the "device" - they only needed a shoebox and a damp sponge - meant that for five months, from June 1918 until the end of the war, the slugs became part of the team. campaign of American soldiers.