This textbook is designed as a pupil's book for use in the primary grades of schools, both public and private. It is so written that the subject-matter can be read and understood by pupils who are able to read well. While stating in simple language some elementary facts in anatomy and physiology, especial attention has been given to rules for the preservation of health. A careful search for the cause of the physical ills of adult life reveals the fact that much of the suffering is the result of repeated violations of hygienic laws early in life. It is no mitigation of these ills that the laws are violated through ignorance; but the fact that most of the violations occur from lack of knowledge furnishes a potent reason for training the young with great care. By earnestly presenting the simple truths as laid down in the text of this little book, teachers can exert an influence for good which will be both valuable and permanent. The reward of such effort will be the highest, the development of a wiser, more temperate, and more moral people.