During his time as the government advisor with the Imperial Department of Health in Berlin in the 1880s, Robert Koch became interested in tuberculosis research. At the time, it was widely believed that tuberculosis was an inherited disease. However, Koch was convinced that the disease was caused by a bacterium and was infectious, and tested his four postulates using guinea pigs. Through these experiments, he found that his experiments with tuberculosis satisfied all four of his postulates. In 1882, he published his findings on tuberculosis, in which he reported the causative agent of the disease to be the slow-growing "Mycobacterium tuberculosis". Later, Koch's attempt at developing a drug to treat tuberculosis, tuberculin, led to a scandalous failure: he did not divulge the exact composition, and the claimed treatment success did not materialize; the substance is today used for tuberculosis diagnosis.