Transcript: British Army source documenting the impact of gas attacks, 1917

(Catalogue ref: WO 32/5176)

Chemical and physiological examination has shown this liquid to consist principally of dichlorethyl sulphide, the other constituents being apparently only ordinary impurities resulting from the process of manufacture. The vapour, even when highly dilute, attacks the eyes and causes conjunctivitis, but the results are not felt until some hours after the exposure. If the vapour is breathed in sufficient quantity it also attacks air passages, and may lead to death from pneumonia.

If the liquid comes into contact with the skin and is not perfectly removed at once, after a few hours it causes blisters which as a rule are very persistent. The great danger of blistering is from the spray of a bursting shell falling on the clothes, or from sitting on the ground or on objects which have received some of the liquid.

The most likely cause of the eyes or respiratory system being attacked is omission to put on the mask during a shell attack; or after the attack is over, during occupation of the ground; remaining for any considerable time in a dug-out into which the liquid has penetrated is almost sure to cause affection of the eyes, chest or skin, or all.