In my last email I quoted Dirac and Agnes Boskovitz of ANU asked me for a reference. In fact I have quoted before in `Out of Line' "Mathematics also leads science. The great physicist, Paul Dirac, in one of his last addresses, explained his own credo (quoted in [12] p.63): "One should allow oneself to be led in the direction which the mathematics suggests... one must follow up a mathematical idea and see what its consequences are, even though one gets led to a domain which is completely foreign to what one started with.... Mathematics can lead us in a direction we would not take if we only followed up physical ideas by themselves." [12] Ferris, T., The world treasury of physics, astronomy and mathematics, Little, Brown and Co., 1991. The quotation is in the article in this volume taken from `The second creation' by R.P. Crease and C.C. Mann (Macmillan, 1986). I do not have any more information than that and any more would be welcome. Ronnie