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Preface The approach to understanding hydrogen ion behavior that is presented in this book has been developing ever since, as an undergraduate chemistry major, I first confronted the confusion surrounding biological uses of the terms "pH" and "buffer." The derivations and discussions always seemed so circular and frustrating. No general answer was ever given to the question "What is it that determines hydrogen ion concentration in a solution?" and that surely is the first question! When, about 1973, I finally worked out the astonishingly simple answer to that question, computers had arrived, and it suddenly became easy to use the answer in satisfyingly practical ways. Continuing feedback since then, from colleagues and from graduated students who are now practicing physicians, research scientists, and teachers, has reinforced my conviction that doing it right is much easier than it looks, and that understanding is more powerful than memorized formulas. A result of that conviction is that this book is most rewarding when studied and thought through, rather than just read. Because this approach is so different from the classical and historical one, I have tried to keep them separate, and to start fresh and uncluttered by the limitations of precomputer science. Despite many urgings, I have therefore largely omitted references to the historical development of "acid-base" in biology and medicine. I have also assumed that anyone who reads this book will have some useful acquaintance with general chemistry, biology, and mammalian physiology, so that references to particular textbooks are not needed when kidneys, lungs, osmolarity, and so forth are mentioned. For both these reasons, almost no references to the literature are presented. The development of the subject is sufficiently self-contained that detailed references should not be needed at this stage. When they do become necessary, readers can supply their own from the enormous relevant literature. It should also be clear from the beginning that there is nothing sacred, guaranteed, or absolute about the numerical values used here. In my own perusal of the literature, I have been amazed at the range of values quoted as "true" or "correct" or "best." From that range, I have assembled some idiosyncratically weighted averages to use here. If you don't like any of them, please use your own favorite values. Precise numerical values, even if they were meaningful, are not the point of this story. The results we get, and the principles involved, are illustrated by the many computer-plotted curves throughout the book. Adjusting their scales to fit "better" or "preferred" parameter values is easily accomplished, and will not affect the arguments or conclusions. So many friends, critics, and fellow students of all sorts have contributed to the development of this book that it would be impossible to acknowledge them all. It is also difficult to rank their contributions. Sometimes pages of detailed criticisms, sometimes just a few casual words or just the right question were needed to unlock a longstanding problem. I am extremely grateful to all who have thus contributed. None of them, of course, bears any responsibility for the remaining defects. Special thanks must go to the following who have provided crucial help of many sorts: V. Fencl, G. Filly, R. E. Forster, P. M. Galletti, J. Gamble, L. Homer, D. Jackson, N. Kindig, A. Portela, B. Reeves, and B. T. Stewart. Paul Palatt and Wayne Thornburg, both now deceased, provided continuing stimulation and encouragement, each in his special way. They are sorely missed.
Peter A. Stewart |
