Suspense's "The Man Who Knew How" was adapted from the short story by Dorothy L. Sayers, which was first published in Harpers Bazaar in February 1932. Suspense's version adds a little more to the ending, but otherwise, it is presented as written. The original story is available online at Google Books.
As the episode opens, Mr. Pender strikes up a conversation with a fellow passenger on a train. He offers the man a mystery to read, but the stranger declines the offer. The murders in mystery books are far too inadequate for him because the criminals always get caught. He is more interested in the murderers who don't get caught. Then, he mentions that one could easily kill someone without detection by using a few simple chemicals. . . .
adapted for radio by Evelyn Keller and produced/directed by William Spier.
The video is complete with vintage commercials. I don't usually post adaptations but I love Charles Laughton and Hans Conried. They really knew how to create the impression of being in a location. Some newer ones do a good job but I think some of them could do a bit more with subtly used sound effects.
The beginning of this reminded me of a radio play I posted a long time ago, if you missed it you might like David Pownall's The Man Without The Mobile. You might like it if you didn't miss it.