Seriously? And here I finally found the context for the gas thing. He was doing a BBC broadcast during the lead-up to WWII, discussing disarmament talks. In typically Shaw style, he acknowledged that the talks were not about disarmament at all, but an effort to make deals on what kind of bombs the Germans and British were going to kill each other with. There is a page missing, but the topic is consistent. He was saying it looks like we're all going to kill each other after all in a bloody, horrible war, so it would be nice if we could do it with a painless, humane gas rather than blowing each other to fragments of bone and gore.
Bernard Shaw and the BBC - Leonard W. Conolly - Google Books
I hope I have reassured you.