Of Dr. _Frank Overton's_ three books on _Applied Physiology_,[64] the first or primary grade follows a natural order of treatment, presenting in each subject elementary anatomical facts in a manner that impresses function rather than form, and from the form described derives the function. The facts and principles are then applied to everyday life. The intermediate grade, besides being an introduction to the study of anatomy and physiology, is intended to be a complete elementary book in itself, giving a clear picture of how each organ of the body performs its work. The advanced grade book was suggested by a series of popular lectures in which the author presented the essential principles of physiology about which a physician is consulted daily. His explanations of many common facts were novel to his auditors, and it was found that the school books were silent upon many of these points, especially with regard to the cells. Throughout the series the fact that the cells are the units in which life exists and acts is emphasized. The author has endeavored to include all the useful points of the older text-books, and to add such new matter as the recent progress of physiological and hygienic science demands. Avoiding technical terms, he has sought to express the truths in simple language, "such as he would use in instructing a mother as to the nature of the sickness of her child." The subjects of alcohol and other narcotics are made prominent in all the books, and are discussed fully in the third of the series. The relation of respiration and oxidation to the disappearance of food, to the production of waste matters, and to the development of heat and force, is dwelt upon. Simple and easy demonstrations, many of them new, are provided at the ends of chapters. A chapter on Repairs of Injuries, or the restoration of the natural functions, when impaired, by the body, is new in a school textbook.