THE ANALYSTTHE ANALYTICAL JOURNAL OF THE CHEMICAL SOCIETYEDITORIAL ADVISORY BOARD*Chairman: J. M. Ottaway (Glasgow)R. Belcher (Birmingham)L. J. Bellamy, C.B.E. (Waltham Abbey)L. S. Birks (U.S.A.)E. Bishop (Exeter)L. R. P. Butler (South Africa)E. A. M. F. Dahmen (The Netherlands)A. C. Docherty (Billingham)D. Dyrssen (Sweden)W. T. Elwell (Birmingham)J. Hoste (Belgium)H. M. N. H. Irving (Leeds)M. T. Kelley (U.S.A.)W. Kernula (Poland)'J. H. Knox (Edinburgh)G. W. C. Milner (Harwell)"H. J. Cluley (Wembley)"P. Gray (Leeds)G. H. Morrison (U.S.A.)H. W. Nurnberg (West Germany)E. Pungor (Hungary)D. 1. Rees (London)"R. Sawyer (London)P. H. Scholes (Sheffield)'W. H. C. Shaw (Greenford)S. Siggia (U.S.A.)"D. Simpson (Thorpe-le-Soken)A. A.Smales, O.B.E. (Harwell)*A. Townshend (Birmingham)A. Walsh (Australia)T. S. West (Aberdeen)"J. Whitehead (Stockton-on- Tees)A. L. Wilson (Medmenham)P. Zuman (U.S.A.)'G. E. Penketh (Billingham)"Members of the Board serving on The Analyst Publications CommitteeREGIONAL ADVISORY EDITORSDr. J. Aggett, Department of Chemistry, University of Auckland, Private Bag, Auckland, NEW ZEALAND.Professor G. Ghersini. Laboratori CISE, Casella Postale 3986,201 00 Milano, ITALY.Professor L. Gierst. Universit6 Libre de Bruxelles, Facult6 des Sciences, Avenue F.-D. Roosevelt 50,Professor R. Herrmann, Abteilung fur Med. Phy!;ik., 63 Giessen, Schlangenzahl 29, W. GERMANY.Professor W. A. E. McBryde. Faculty of Science. llniversity of Waterloo, Waterloo, Ontario, CANADA.Dr.W. Wayne Meinke. KMS Fusion Inc.. 3941 Research Park Drive, P.O. Box 1567, Ann Arbor,Dr. 1. Rubeika, Geological Survey of Czechoslovakia, Kostelni 26, Praha 7, CZECHOSLOVAKIA.Dr. J. RfiSiEka, Chemistry Department A, Technical University of Denmark, 2800 Lyngby, DENMARK.Professor K. Saito, Department of Chemistry, Tohoku University, Sendai, JAPAN.Dr. A. Strasheim. National Physical Research Laboratory, P.O. Box 395, Pretoria, SOUTH AFRICA.Bruxelles, BELGIUM.Mich. 48106, U.S.A.Published by The Chemical SocietyEditorial: The Director of Publications, The Chemical Society, Burlington House,London, WIV OBN. Telephone 01 -734 9864. Telex No. 268001Advertisements: Advertisement Department, The Chemical Society, Burlington House, Piccadilly,London, WIV OBN. Telephone 01 -734 9864Subscriptions (nonmembers): The Chemical Society, Distribution Centre, Blackhorse Road,Letchworth, Httrts., SG6 1 HNVolume 104 No 1234 January 19790 The Chemical Society 197