The third edition of this book represents the twelfth printing. The author has made slight changes in recognition of some of the newer knowledge that has been developed in modern medicine. The book has so well established itself as a reliable reference in its field that it does not seem to be advisable to undertake a general revision and rewriting. Dr. Williams writes authoritatively, fearlessly, and invariably with interest. Not so much can be said for most of the books on personal hygiene now available.