USED IN DENTAL SURGERY. 117 



arsenic, which is its absorbability, and the conse- 

 quent inflammation and death of the pulp, and 

 irritation and inflammation of the peridental mem- 

 brane. I confess that I have not found this to 

 occur to such an extent as some practitioners 

 record ; but it is, undoubtedly, too often the case, 

 and must make us regard arsenic as occupying 

 its present position in our list of remedies only 

 till a safer preparation shall be discovered. 



Some years ago. Dr. Arthur brought into notice 

 the ore of cobalt, the escharotic properties of which 

 are due to the presence of large quantities of 

 arsenic in it. The cobalt being insoluble, the 

 arsenic is not so likely to be absorbed by the tooth. 

 Dr. Arthur places the one-twentieth part of a 

 grain in the cavity of decay, covering it in with 

 wool moistened with a solution of gum sandarach 

 in alcohol, and leaves it there from twenty-four to 

 forty-eight hours, according to the depth of the 

 cavity ; and after removing it, 'he waits for about 

 the same length of time before commencing to 

 operate. He seems to have obtained great advan- 

 tages from its use ; but I cannot speak so highly 

 of it from my own experience. I did not, in- 

 deed, find that any inflammation of the pulp or 

 peridental membrane followed its employment; 

 neither, however, did the sensibility of the dentine 

 appear to be at all lessened. 



In comparing chloride of zinc with arsenious 

 acid, therefore, the former is quicker in its effect ; 



