This is a bit of an odd question and no, I'm not planning on poisoning anyone. I bought the old b/w 50's movie D. O. A. on dvd at Walmart for a buck and at the end there is a statement from the movie's technical advisor that the movie was based on real medical fact and that "luminous poison" is a descriptive term for a real poison. Apparently a test for the substance involves luminescence. Anyone know what this substance is? This has bugged me ever since I first saw the movie many years ago.