Practical advice on marital relations and sex, first published in 1897. The Preface explains: "In approaching the work which we have undertaken in these pages, we have not been blind to the difficulties which confront us in entering upon so delicate a subject. If we had thought only of these, we would never have taken up our pen in this work. We have been moved to it by the cries of disappointment and anguish which may be heard everywhere throughout our land, and by the pleadings that come up out of the dense ignorance which envelops palace and hovel alike. Knowing the importance of these "matters which are so central in our physical life, so essential in their relation to the condition, character, career and destiny of every individual, and so fundamental and vital to every institution and interest of society;" knowing also the importance of proper intelligence concerning the laws which govern our bodies, and knowing how the honest and the pure who seek information concerning these most sacred relations of human life are exposed, amid the dearth of pure and reliable books, to contamination by books whose secret character designedly fosters the very lusts and evils which they are professedly written to denounce, we have felt that we would be recreant to duty, to humanity and to God if we allowed difficulties to bar us from this important work."