 In addition to his judicial work, Hartwich exerted himself in promoting the physical education of the young, published several writings on the subject and took part in founding the Association for Promotion of Personal Hygiene (Zentralvereins für Körperpflege in Volk und Schule).In the summer of 1881 Hartwich, who was suffering from the throes of his unhappy marriage, became acquainted with young Elisabeth von Ardenne, who was ten years his junior.She had recently arrived in Düsseldorf together with her husband Armand Leon von Ardenne, due to Armand's ascent within the country’s political hierarchy.