€18 PKOCEEDINGS OF THE SOCIETY. 



bility of stopping an unpleasant disease, but also the great question of 

 the connexion of the bacteria dealt with, with other groups, such as 

 the ostoria, since there was a laige tield open for such work. 



Dr. John Eyre said that pyorrhoea was a subject to which he had 

 devoted intermittent attention for some fifteen or eighteen years, and 

 he was delighted to find himself largely in agreement with the opinions 

 expressed by the authors of the evening's paper, particularly when they 

 scoffed at the idea that amoebas were the cause of pyorrhoea. 



His own opinion coincided with theii's, that pyorrhcea was the 

 direct result of gum infection — i.e. a direct inoculation of the virus, 

 whatever it might be, into the gum tissue, genei'ally by the aid of some 

 sliarp lacerating instrument, such as a spicule of bone, a bristle from a 

 tooth-brush, or a scaling instrument, and the resulting inflammation 

 resembled that occurring in other fibrous and bony tissues, plus certain 

 modifications due to its anatomical position. Moreover, as it was well 

 known that the ordinary pyogenic bacteria which caused pus in other 

 situations would give rise to suppuration in the gum and alveolar 

 process, he considered they were the probable cause of most cases of 

 pyorrhcea. 



He was anxious to know whether the cases in the lower animals fi'om 

 which the authoresses obtained their excellent sections were artificially 

 produced, or whether they were selected natural infections ; and, if the 

 former, how the authors were able to keep up the infection experi- 

 mentally so as to secure the late stages of the disease. He had himself 

 tried many times to produce pyorrhoea artificially in the rabbit and 

 guinea-pig, but, so far, had only succeeded in producing a transient 

 marginal gingivitis. Of course, he had seen cases of pyorrhoea occurrimr 

 naturally in animals, but considered it was difl[icult to get a series of 

 sections of the beauty of those Mrs. Goodrich had shown. 



With regard to the possibility of the author's pleomorphic leptothrix 

 being a possible source of the Bacillus fusiformis of Vincent, he did not 

 think that assumption would prove to be correct, since the fusiform 

 bacillus had been cultivated and had bred true in culture media from 

 generation to generation ; it had never developed either into spirochiete 

 on the one hand, nor into leptothrix on the other. 



He would like to hear Mrs. Goodrich's opinion of Nogouclii's work 

 on the spirochfetes as the cause of pyorrhoea. 



Mr. E. J. Sheppard said that after some twenty years beside the 

 dental chair he could not resist the personal conclusion that, excluding 

 the leptothrix theory, the expounding of which had interested him 

 greatly, far too great importance was attached to the bacterial theory of 

 the causation of pyorrhoea. The development of tartar as a cause he 

 also thought was over-rated. He considered it due to some altered 

 metaboUsm of the cells, a view which had not received due attention. 

 Though a dentist, he was himself subject to pyorrhcea, and to rid 

 himself of it he had tried everything at his disposal. Yet he was still 

 as far from cure as when the condition first developed. In connexion 

 with the view as to a systemic cause, he believed a wide field was 

 open for the practice of vaccine therapy. 



Dr. Leeson thought there was a constitutional element in pyorrhoea 



