OPERATIONS ON THE TEETH. 337 



lum, and tlie tongue drawn out and held on one side by an assist- 

 ant, or whether the operator himself controls the tongue with one 

 hand while working the instrument with the other, the manipula- 

 tions must be the same, viz. : the passage to and fro of the file over 

 the surfaces requiring to be corrected, wherever they are rough 

 and sharp ; filing them just as the smith files the iron he is shap- 

 ing as he holds it in the vise. We believe, however, that the 

 rasping out ought to be done slowly, softly and without giving the 

 animal any cause for fright or excitement. The method sometimes 

 practiced of vising the rasp with a succession of rapid movements 

 over the dental arches is certainly dangerous and liable to be ac- 

 companied with accident to the patient. An irritable, struggling 

 animal, by violent movements of the head, or in his attempts to 

 chew on the rasj), may easily receive injuries from the rough con- 

 tact of the instrument with the delicate structures of the mouth. 

 After such a passage of the rasp a number of times over the teeth, 

 the hand introduced in the mouth will at once detect the effect 

 upon the patient. 



Although the use of the speculum may be advantageous in 

 many instances, there is certainly a risk attending its use, in the 

 possibility of bruises and lacerations which may occur at the bars 

 when the animal, annoyed by its application, chews upon it in his 

 endeavors to close his mouth. 



The work of filing when the teeth are sharp is of common in- 

 dication, and finds its direct appUcation under the special condi- 

 tion that the edges or asperities which are treated should not be 

 too large or too prominent. If this should be the case, and the 

 inefficiency of the file or rasp, however, become evident in the trial, 

 other means remain for accomplishing the desired pui-pose. Such 

 a contingency was not lost sight of in former years, and chisels 

 and gouges were then employed to reduce the excessively devel- 

 oped projections of enamel. 



With these instrimients the patient was either thrown or treat- 

 ed on his feet, his mouth being opened with a speculum, with his 

 tongue di-awn out and held on one side. The chisel was then laid 

 against the dental projection, and an assistant striking it with a 

 hammer, the excess of tooth was knocked off. Bouley considered 

 this mode of operation dangerous. " The chisel might, under the 

 impulse received by the hammer, slide in the mouth and severely 

 injure the tongue, the cheeks, and the soft or the hard palate ; or 



