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Adsorption on and Surface Chemistry of Hydroxyapatite. D.N. Misra (Editor). Plenum Press, New York, 1984, viii + 179 pp., US$39.50.

This volume contains 10 papers, most of which were given at a symposium during the American Chemical Society meeting in Kansas City in September 1982. As the editor says “hydroxyapatite is the structura! prototype of the main inorganic constituent of bone and teeth”. There is therefore a great deal of interest -& its properties particularly its inter-facial properties. Even the model compound Ca,,(PO,), (OH):! is remarkably complicated in its surface ionic equi- libria. Most of the papers are concerned with studies of colloidal suspensions hav- ing ill-defined structures and surfaces. Measurement of adsorption from multi- component solutions with an interpretation based on the Langmuir is not an il- luminating approach. Fortunately, more specific techniques are beginning to be applied, the emission of low energy electrons and NMR are described in two of the papers. Even the combination of electrophoretic measurements with adsorp- tion studies seems a step in the right direction.

As always with a volume of this type one wonders why this group’of papers should merit a special volume. There is no special organisation. The most intro- ductory paper is placed third. Perhaps publication in this form may bring this im- portant subject to the attention of electrochemists and physical chemists who do not normally read J. Dent. Res. or Oral Biol.

ROGER PARSONS Bristol