The format of this edition remains unchanged from previous editions but the majority of entries have received some revision. In particular, units are now in SI units wherever possible, although with certain of the classical entries this is not possible. Chemical terminology has proved a particular problem. We have kept the common names for organic compounds because of the wide readership of this book but we have added an extra table giving the equivalent systematic names and the formulae. We have tried to avoid omission of any named effects and laws that have wide usage. Nevertheless, in...