Doutrelepont has recently described in the transactions of the German Dermatological Society, _On the Pathology and Therapeutics of Leprosy_, a lung affection, probably developed by tuberculine treatment, which he diagnosed from the examination of the sputum. But the patient had a leprous affection of the larynx, and his account by no means excludes the possibility that the bacilli in the sputum came from a ruptured nodule in the larynx, possibly softened by the tuberculine treatment. We cannot, therefore, recognise this observation as infallible evidence of the presence of a leprous lung affection, any more than that case of leprosy of the lungs described by Bonome in _Virchow’s Archiv_, Bd. C. That author himself draws attention to the great resemblance of the affection to tuberculosis, and as it is quite evident from his description of the bronchial lymphatic glands that they were not leprous, and he notes the presence of giant cells in the pathological products, we cannot doubt that it was really a case of tuberculosis. In the same case there was found an affection of the spinal cord, from which Bordoni-Uffreduzzi cultivated on glycerine agar an organism which he recognised as the lepra bacillus. Here we may remark in the first place that we have never seen a leprous affection of the spinal cord, and have never found bacilli in it. We must indeed admit that we have only examined the spinal cord in a few cases, because there appeared to be no indication for such an examination, since clinical symptoms do not point to an affection of that organ, and as in the profusely nodular cases, affections easily recognised appear everywhere, except in the liver and spleen, it was to be expected that an affection of the spinal cord would have been recognisable. In necrotic bones, which we have often examined, nothing leprous is found. This necrosis is therefore no specific leprous affection, but a secondary one. Secondly, we must remark that in spite of many attempts we have never succeeded in cultivating lepra bacilli on glycerine agar. We therefore believe that Bordoni-Uffreduzzi has cultivated tubercle bacilli instead of lepra bacilli. The only thing which speaks for the leprous nature of the lung affection and the cultivated bacilli, is the circumstance that the author did not succeed in inoculating guinea pigs and rabbits with tuberculosis. But, according to all investigations on tuberculosis, it appears to us not incredible that the tubercle bacilli may, under circumstances, become so weakened that they are no longer pathogenic.