Nitrogen tri-iodide, or more accurately the complex between it and ammonia ranks amongst the oldest known molecules (1812). I became familiar with it around the age of 12-13, in an era long gone when boys (and very possibly girls too) were allowed to make such substances in their parent’s back gardens<sup>‡</sup> and in fact in the school science laboratory,<sup>†</sup> an experiment which earned me a personal request to visit the head teacher.