186 Transactions of the Society. 



was deemed advisable by us to publish the paper as it stands in 

 the li^ht of a preliminary commuuication. 



The parasitic amoeba of the mouth was originally described by 

 Gros in 1849, and since that time many observers have considered 

 it to be the chief causal agent in pyorrhoea. Bass and Johns, for 

 instance, in their recent work {!)* consider that the Entamoiba 

 huccalis is the causative organism in pyorrhoea, and that destruction 

 of the amoeba by means of emetine is the care of the condition. It 

 therefore seemed desirable to make use of the very large amount 

 of material passing through our hands at the Dental Hospital to 

 endeavour to settle the questions (1) whether amoebse are invariably 

 associated with pyorrhoea ; (2) whether more than one species of 

 amoeba exists under such conditions ; (3) the possible pathogenicity 

 of such amcebse ; and (4) the possible relationship of other organisms 

 to the condition. 



Technique. 



Examination of material taken by means of the technique de- 

 scribed by the majority of authors gave very inconsistent and 

 disappointing results, and it was clear that to study these questions 

 properly a better method of obtaining material from the patients 

 was necessary. 



The method finally adopted, and by means of which the whole 

 of this work has been carried out, is as follows : — 



A glass tube is drawn out in the flame so as to form a Pasteur 

 pipette ahout 6-8 cm. in length. The fine extremity is then 

 softened in the flame and quickly drawn out to capillary thickness. 

 This is cut off about 1 cm. from the end, and then turned up 

 at a right angle so as to form a pipette of the shape shown in 

 fig. 1. A. little 0*5 p.c. saline is allowed to run into the fine 

 extremity by introducing the point of the pipette into a test tube 

 containing the fluid, and the pipette is ready for taking the 

 material. The patient's mouth is examined, and a suitable pocket 

 is selected, and the capillary portion of the pipette is then intro- 

 duced into the pocket and pushed up to the top of the floor, 

 and then gently drawn along, and finally withdrawn. The material 

 contained in the pocket enters the pipette by capillarity, and mixes 

 with the saline. For routine examination, the contents of the 

 pipette are blown out on to a glass slide, and mixed by drawing up 

 into the pipette and blowing out again, two or three times. A few 

 drops of the resulting emulsion are placed on a slide, a cover- 

 glass is applied, and at once sealed by running melted paraflfin- 

 wax round the edges. The preparation is then examined with the 



* The figures in brackets refer to the Bibliography at the end of the paper. 



