In a book of this nature, which deals with the concepts greatly opposed to the usual therapeutic-dietetic procedures, the reader is confronted with the difficulty of weighing evidence. Any one who has ever attempted therapeutic experiments, especially those involving diet, has realized the difficulties of interpreting results. Probably to appraise the importance of the present contribution would require a set of control experiments. Since this is obviously impossible all one can say is that the book reads like an interesting story but naturally causes a certain feeling of doubt. It is somewhat difficult to conceive that the changes in salt and water metabolism have such a marked influence on such varying diseases as epilepsy, angina, gout, essential hypertension and acne vulgaris. The only way properly to assay the value of this book would be by the experimental method.