This book deals with the history of Centenarians and Lessons from their Habits.
"... as has been well said, "the harmonious development of the many-sided aspects of man is conducive to health and the prolongation of life," and that there need be no fear of entering heartily and actively, and with full interest and energy, into the assigned work of life, physical or mental. The body is made, not for ease and sloth, but for labor and play, for work and enjoyment, better still for enjoyment of work. Work, enjoyed as it should be, promotes health in body, and especially if stimulated by other motives than personal ambition and gain, engenders that cheerful, placid frame of mind which is one of the adjuncts of centenarianism...”
REF : 9782366594577