The technique of electron probe X-ray microanalysis (XRMA), by which the elemental composition of specimens can be determined on a microscopical scale, has now been applied to biological materials for about 30 years, and in that time has made many valuable contributions to a variety of biological problems. To improve awareness of the technique, and to provide a discussion forum for those interested in biological XRMA, the Biological X-ray Microanalysis Group was formed in Britain some five years ago. Although its primary purpose was to hold regular meetings, the possibility of producing a book which reviewed both developments in the equipment and the wide variety of applications for which XRMA could be used was another aim, now realised in the present volume. This book arose out of a meeting held by the Biological X-ray Microanalysis Group in Manchester, England, in April 1991. What we have tried to produce is not simply another set of conference proceedings, but a well balanced and integrated series of chapters describing the hardware and software used for XRMA, the necessary procedures for specimen preparation and quantification, and the enormous range of applications of the technique in biology.

It might be supposed that after 30 years' application of biological X-ray microanalysis, the field might be settling down to a comfortable but perhaps rather routine maturity. The contributions in this book show, however, that this is far from being so, with many exciting developments in all aspects of the subject.