Although the original plan of the book, the arrangement into twenty-six lessons, remains unchanged, the author has subjected the text to such revision as was necessitated by the increased and more exact knowledge of chemical physiology. The chapter on protein has undergone the greatest change, and is far more extensive than it was in previous editions. The sections relating to coagulation of the blood and to respiration have also been carefully revised. Many new illustrations are added, thus increasing the value of the book. The appendix is deserving of special mention, inasmuch as it details the use of apparatus which should be found in the laboratory of every practitioner.