Massive and early study of puberty among Europeans, with comparative data including mortality tables. Daignan was especially interested in the plight of urban youth. He concluded his work with tables of life expectancy based on variables of age, constitution, stature, physique, climate and soil, sex, occupation and disease. He reported the survey of 10,000 individuals with respect to mortality according to sex, age and occupation. Digital facsimile from BnF Gallica at this link.