Foreword

The general format of the Digest has not been changed this year and, in keeping with the policy established last year the chapter headings are the same. The chapter on “Molecular and Ionic Interactions in Dielectrics” has been divided into two separate chapters, however, entitled “General Theoretical and Experimental Work” and “Chemistry”. It was felt by the authors that, even though a certain amount of duplication might occur the separation was logical and would result in greater ease of preparation.