This textbook has not been reviewed in this Journal since its third edition in 1982. As a result it is not possible to detail all of the changes that may have occurred since then and persisted into this latest edition. Nevertheless, it is clear from inspection that the basic structure of the seventh edition, including the ordering of chapters, is essentially the same as it was in the third edition. The main difference is that the current edition has just nineteen chapters in all, one fewer (despite the brief contents listing only the first seventeen of them) than the third edition. Apparently the two chapters on organic chemistry have been incorporated into one.

Despite the reduction in the number of chapters the current cloth edition has 656 pagesa paperback alternate edition contains the first seventeen chapters, 496 pagescompared to 596 pages in the earlier reviewed edition. The increase in the number of pages is no doubt largely accounted for by the new features announced by the publisher. These include (i) a countdown section as a bridge at the beginning of each chapter except the first; (ii) study exercises, problems with answers strategically inserted into the text; (iii) marginal "you and chemistry" icons highlighting real-world material in adjacent text; (iv) end of chapter essays on elements and compounds; (v) content changes on calculating oxidation numbers in chapters 6 and 16, on molecular shapes (VSEPR) in chapter 6, on dilution of molar solutions in chapter 14 (conversion of solution concentration deleted), on colloids and suspensions in chapter 15; (vi) revised essays on chemistry of the atmosphere; (vii) addition of over 100 new problems; (viii) marginal study hints and end-of-chapter summaries and quizzes. Students and/or instructors will find some if not all of the pedagogical devices incorporated in items i-iv and vi-viii above useful in learning and teaching chemistry, respectively. It is difficult to judge the effectiveness of any one of them without actually having used the text. However, I will express some opinions below. The changes in contents listed in item v presumably have been made based on experience and therefore should be improvements. In any case, none of the changes is so major that the book loses its basic character.

My favorites among the pedagogical devices noted above are the end-of-chapter essays on elements and compounds and the revised essays on chemistry of the atmosphere. In these the author becomes more expansive and his writing style more attractive. Not that there are no difficulties or flaws in these essays. There are. But in a sense that is part of their attraction and even strength. For example, I was a bit disappointed that little effort was made in the essays on gold, silver, and copper to compare these elementsthese chemical siblingswith one another, prospectively in the case of gold and silver, and retrospectively in the case of silver and copper. But really, it is at least in part the job of the instructor to use these essays to help students make connections that will enrich their understanding and appreciation of chemistry. In this light, the fact that the essays are there is much more important than perceived flaws.

Nevertheless, I cannot contain my unhappiness at the way carbon dioxide is mistreated in a number of the essays. The essay on carbon dioxide at the end of chapter 9 is seriously deficient in that it never mentions explicitly the fact that carbon dioxide is essential to most, if not all, life on earth and that it is the only source of oxygen in our atmosphere through its metabolism by plants, algae, and certain bacteria. Instead, we are warned that "Humans cannot breathe air containing more that 5 to 10% CO₂ without losing consciousness, and prolonged exposure can result in death." I think the author has things terribly muddled here. The effect on humans more likely is due to oxygen deficiency rather than on CO₂ accumulation per se. In addition we are referred to another essay on pollutants in the atmosphere in which CO₂ is identified as one. Finally, in an essay at the end of chapter 11 on the greenhouse effect and global warming, CO₂ is identified as an atmospheric greenhouse gas along with three others (the most important greenhouse gas, water vapor, is never mentioned) completing an undeserved negative picture of CO₂ as a trace pollutant, greenhouse gas, dangerous to humans in high concentration. Considering the fact that CO₂ plays essential roles in sustaining life, including its role in stimulating autonomic breathing in humans and no doubt in other mammals, this negative image is really undeserved. Despite these deficiencies even these essays pertaining to CO₂ can be used by the instructor positively to point out, as I would, what a good guy CO₂ really is despite its bad press. The presence of the essays is again at least as important as their content.

The new feature that I found least attractive was item iii, the marginal icons, which seemed to me of dubious pedagogical value. Their placements depend on judgmentbased on what criteria I am not sureof the relevance of adjacent text to a prospective unknown reader. Their presence has the effect of someone other than the reader highlighting certain text passages. However, with fewer than one hundred icons in over six hundred pages they are not at all overused.

The seventh edition of this textbook contains a number of new features that enhance its pedagogic utility while the basic character and structure exhibited in earlier editions are maintained. Potential users who liked an earlier edition will probably like the seventh edition even better. For prospective new users it is worth looking at seriously.