 He died in Berlin, aged 74.He is remembered for his pioneer work involving testicular puncture biopsy in the investigation of infertility in humans, as well as for the eponymous "Posner test", a means used for determining the presence of albumin in urine.In addition to his works associated with genitourinary subjects, he published a biography on pathologist Rudolf Virchow (1921) and an important study involving the lamellibranch gill, titled ""Ueber den Bau der Najadenkieme.