PREFACE. Agesilaus, king of Sparta, when asked what things boys should learn, replied, “Those which they will practise when they become men.” As health requires the observance of the laws inherent to the different organs of the human system, so not only boys, but girls, should acquire a knowledge of the laws of their organization. If sound morality depends upon the inculcation of correct principles in youth, equally so does a sound... more...