Today, I came across an article in The Telegraph in which in 2013, a historian and author named Giles Morton claimed that Winston Churchill was going to use something called the M Device against the Russian Bolsheviks to help the Whites win the Russian Civil War. According to Spartacus Educational who quoted Giles Morton... "Trials at Porton suggested that the M Device was indeed a terrible new weapon. The active ingredient in the M Device was diphenylaminechloroarsine, a highly toxic chemical. A thermogenerator was used to convert this chemical into a dense smoke that would incapacitate any soldier unfortunate enough to inhale it... The symptoms were violent and deeply unpleasant. Uncontrollable vomiting, coughing up blood and instant and crippling fatigue were the most common features.... Victims who were not killed outright were struck down by lassitude and left depressed for long periods." The accompanying article in Spartacus Educational also showed a picture of what looked like a British soldier handling a shell which was the so-called 'M Device'. https://spartacus-educational.com/spartacus-blogURL5.html Now, here's my question. Since this came from one historian, I'm sceptical as to whether this is legitimate or not, so I wanted a second opinion. In your opinion, is this story legitimate or is this just a yarn spun by a historian looking for attention?