Ever since the first volume appeared in 1969, this series has received good reviews in a variety of periodicals published in different corners of 'the world. It would seem that the work has fulfilled its purpose as outlined in the Preface to Volume 1. The rapidly increasing interest in surface and colloid science by people engaged in industrial research and development, and in environmental, ecological, medical, pharmaceutical, and other areas, justifies the continuation of such an effort. After nine volumes with John Wiley and Sons, this and subsequent volumes will-by mutual consent-be published by Plenum Press. The editor will do his best to maintain and, if possible, improve the quality of the contributions. While the fundamental philosophy will be preserved, some moderate graphical changes have taken place. These changes were done to enhance the readability and uniformity of the volumes. Occasionally, volumes may appear under the editorship of other scientists in the field. These volumes will be mainly devoted to techniques in surface and colloid science. For reasons of continuity a sequential numbering system will be used.