I was working on my PhD with Martyn Symons at Southampton University (1957-1960) and had somre of your yellow pyridinium iodide and was trying to measuer the uv spectrum of your contant ion pair. I believe that Martyn met you and you gave him some. Alan Csarrington, who died recently, was with you for a year at that time and returned to Southampton to do a third year's reseach in order to complete his PhD studies during my time with Martyn.