The experiments of Villemin have not only demonstrated the infectious nature of tuberculosis, but have also led to a more accurate knowledge of the relation between tuberculosis and its allied affections, scrofula and pearly distemper. The anatomical characteristics of scrofula have obviously proved insufficient in determining the relation presented by this affection to tuberculosis. The tendency to cheesy degeneration of its inflammatory {99} products was the feature of chief importance. Villemin showed that portions of a scrofulous (cheesy) gland when inoculated were followed by tuberculosis, and that the inoculation of cheesy material from non-tuberculous or non-scrofulous sources was not followed by this result. The assumption of Buhl, that the absorption of cheesy material, as such, was the cause of tuberculosis, was thus disproved. The frequency with which the inoculation of cheesy material, from what were regarded as scrofulous sources, was followed by tuberculosis, led to more exact studies concerning the anatomical peculiarities of scrofulous inflammation. Köster[57] called attention to the regularity of the occurrence of miliary tubercles in the fungous granulations of the inflamed joints of scrofulous and tuberculous individuals. Wagner[58] and Schüppel[59] discovered that scrofulous glands, in most if not in all instances, were tuberculous glands. The regularity of the presence of tubercles in scrofulous abscesses and ulcers of the skin and in scrofulous caries was shown by Friedländer.[60] This observer likewise called attention to the presence of agglomerated tubercles as the chief constituent of the new formation of lupus. These anatomical discoveries resulted in uniting more closely the affections scrofula and tuberculosis from the histological standpoint, and the union has become more firmly cemented from the etiological investigations. [Footnote 57: _Virchow's Archiv_, 1869, xlviii. 95.] [Footnote 58: _Loc. cit._] [Footnote 59: _Op. cit._] [Footnote 60: _Volksmann's klinische Vorträge_, 1873, lxiv.] Schüller[61] has shown that the introduction of finely divided material from a scrofulous joint--that is, from one containing tubercles--into the lungs of rabbits was followed by a tuberculosis of the tracheal wound, the lungs, and liver. Similar experiments with reference to the introduction of lupus-tissue produced results suggestive of tubercle, if not actually tuberculous. [Footnote 61: _Untersuchungen über die Enstehung und Ursachen der Skrophulösen und Tuberkulösen Gelenkleiden_, 1880.]