120 ON SOME OF THE CAUSTICS 



great pain Avhilst its action is going on, extending 

 usually over several hours, and it is apt to cause 

 injury to other teeth, even with the greatest care 

 in its application. But we constantly meet with 

 cases where it has been perfectly successful ; and 

 though of late years it has been superseded by 

 arsenic, it is, I think, worthy of further trial. 



Arsenic is, however, now almost exclusively 

 employed for this purpose, and is very effectual. 

 Applied in the manner before mentioned, it 

 combines with the albumen of the animal matter, 

 causing the pulp to shrivel and become detached 

 from the bone, so that it can be easily brought 

 away from the whole length of the fang or fangs. 

 I have alluded to the absorbability of this sub- 

 stance, as being the chief objection to its use in 

 diminishing the tenderness of dentine. This objec- 

 tion appHes equally in the present case ; and though 

 I think the danger has been exaggerated, there is 

 still no doubt that the ill effects of the arsenic 

 may show themselves even after the interval of 

 many months, and that such cases are less 

 amenable to treatment than the ordinary inflam- 

 mations of the roots of teeth. Whilst I am 

 penning these remarks, the thought occurs to me 

 that the danger of absorption might possibly be 

 lessened by the incorporation of the arsenious 

 acid with gutta percha, and its application in that 

 state in the form of small pills or masses. As 

 there is no time to try this, however, I throw 



