"The top secret "M Device", an exploding shell containing a highly toxic gas called diphenylaminechloroarsine. The man in charge of developing it, Major General Charles Foulkes, called it "the most effective chemical weapon ever devised". Trials at Porton suggested that it was indeed a terrible new weapon. Uncontrollable vomiting, coughing up blood and instant, crippling fatigue were the most common reactions. The overall head of chemical warfare production, Sir Keith Price, was convinced its use would lead to the rapid collapse of the Bolshevik regime. "If you got home only once with the gas you would find no more Bolshies this side of Vologda."The cabinet was hostile to the use of such weapons, much to Churchill's irritation. He also wanted to use M Devices against the rebellious tribes of northern India. "I am strongly in favour of using poisoned gas against uncivilised tribes," he declared in one secret memorandum."

“A staggering 50,000 M Devices were shipped to Russia: British aerial attacks using them began on 27 August 1919, targeting the village of Emtsa, 120 miles south of Archangel. Bolshevik soldiers were seen fleeing in panic as the green chemical gas drifted towards them. Those caught in the cloud vomited blood, then collapsed unconscious. The attacks continued throughout September on many Bolshevik-held villages: Chunova, Vikhtova, Pocha, Chorga, Tavoigor and Zapolki. But the weapons proved less effective than Churchill had hoped, partly because of the damp autumn weather. By September, the attacks were halted then stopped. Two weeks later the remaining weapons were dumped in the. They remain on the seabed to this day in 40 fathoms of water.”

“The British were no strangers to the use of chemical weapons.”

“Secrecy was paramount. Britain's imperial general staff knew there would be outrage if it became known that the government was intending to use its secret stockpile of chemical weapons. But Winston Churchill, then secretary of state for war, brushed aside their concerns. As a long-term advocate of, he was determined to use them against the.”

“The official website of Giles Milton”