The approach by Hills is based upon two hypotheses: (1) inert gas transport is limited by diffusion in a single radial model of extra-vascular tissue, and (2) nucleation and phase equilibration between dissolved gas and gas in silent bubbles may preclude supersaturation in excess of 74 mmHg. Actually, two different models, not always clearly distinguished, are presented. One, expounded in theoretical analysis is concerned with gas concentration in a certain average sense over the extra-vascular space. The other, used for his proposed optimum decompression method presumes a restraint on point tensions to 74 mmHg over the diffusion field is necessary to preclude nucleation. (Author)

This volume follows and updates AN ANNOTATED BIBLIOGRAPHY ON DIVING AND SUBMARINE MEDICINE published by Gordon and Breach, Science Publishers, Inc., in 1971. The time period covered is primarily the calendar years 1970 and 1971. Also included, however, is much material from the calendar years 1968 and 1969 not in the previous publication. A brief analysis of the sources of material precedes the citations and abstracts, which comprise the main section of the volume. The bibliography is followed by a permuted subject index and an author index. Also included, following the indexes, is a micro thesaurus. Although no attempt has been made to do a critical subject analysis, such an analysis could be accomplished through selecting a particular subject, looking up the appropriate key works in the rotated index, identifying the abstracts, analyzing them, obtaining complete copy as desired, and completing the critical review. David C. Weeks, Ph.D. Director, BSCP Washington, D.C.