When the Entente powers were first exposed to poisonous gas in the spring of 1915 their respective quartermasters scrambled to find a suitable antidote that would save the men in the front line trenches. One of the earliest improvisations was a gauze face mask that covered both mouth and nose, drenched in urine. The attached commercial illustration is from the margins of the French news magazine, "L'Illustration" which depicts one of these earlier attempts. http://www.oldmagazinearticles.com/pdf/INVENTION gaz.pdf
