One person cannot review a book of nearly 700 text pages written by almost 250 authors. He can scarcely hope even to describe it. But he can, in this case, note that if such a book can be written, the editors have chosen a group of contributors who should be able to write it with authority. Drs. Gellis and Kagan have been broad in their selection of subjects to be considered, including not only everything to be expected but also some welcome surprises like the list of Poison Control Centers in the United States and Canada, and some frightening ones like the suggestions for supersonic transport travel.