109 



a local ulceration and not an infective progressive ulceration of the 

 periodontium. 



During the past two years the writer has without exception ex- 

 amined microscopically all suspected cases of Rigg's Disease and 

 before deciding upon treatment has found in all genuine cases the 

 presence of a particular bacterium, which is probably of the anaerobic 

 variety. 



The discovery of this organism led the writer to find an efficient 

 antidote, which from the condition of the parts described in the 

 earlier part of the paper, suggested it should be of the nature of a 

 stimulant, rather than that of a depressant, and so far the medicament 

 has not failed in a single case. 



On the second succeeding day of application microscopical ex- 

 amination showed an entire absence of the micro-organism which were 

 previously plentiful, and there was much less turgidity of the 

 muco - periosteum in connection with the periodontium. The writer 

 has not been as yet able to obtain tissue (either from the living or 

 the recently dead subject) to confirm the supposed connection of the 

 eflects of the organism with the lymph channels. 



The cases which have come under notice, have had histories of 

 duration from a few mouths up to ten years, and even such chronic 

 cases as the latter, which necessarily had been under other treatment 

 to retain any teeth at all, such as copper sulphate, pyrozone etc., 

 answer readily to the prescribed antidote , which consists of green 

 iodide of mercury triturated in a mortar with a little glycerine, to 

 allow of greater readiness of application to the sulci of the affected 

 teeth. The efficacy of the prescription is easily discernable by the 

 fact of the tissues readily bleeding after the first and second applic- 

 ation, which is best done on a small chisel shaped piece of orange wood 

 (metal must not be used) fixed to a small holder — of course using 

 a fresh one in those positions where the teeth are unafiected as an 

 extra precaution, although the writer is convinced that the mercuric 

 iodide is sufficient to destroy an infection, if inadvertently made. The 

 pain and general discomfort disappear and the patient can masticate 

 with comparative ease , even during the early treatment, and the 

 discharge of pus on pressure rapidly disappears, whilst the rouco- 

 periosteum rapidly assumes a more healthy appearance. 



The writer is inclined to look upon this disease as another ex- 

 ample of those affections which accompany a general lowered condition 

 of the mesoblastic element, as a predisposing cause — the real ex- 

 citant being a bacterium. The presence of a special kind of calculus 



