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stitutional treatment, afterwards quickly restored, but 

 from time to time will require attention ; for the teeth 

 that have once been operated on, will, at intervals, 

 ever after during the life of the horse, need the hand 

 of the surgeon. If caries, however, is neglected, 

 and proceeds to the last stage, cure is all but hopeless. 

 During the death of a tooth, the symptoms are con- 

 tinuous. In caries, there are intermissions, seasons 

 of uncertain duration, during which the horse ap- 

 pears to be free from suffering ; but the effects, if not 

 so rapid in their development, are more frequently 

 fatal in their termination. When a tooth has lost its 

 vitality, it becomes a foreign body, which Nature, 

 in time, will cast out. The retention irritates the 

 surrounding structures, but the irritation may in part 

 be regarded as a restorative process. When caries 

 takes place, a portion only dies, but that portion has 

 all the injurious effect which could be attributed to 

 the former case, and even more, for the remaining 

 vitality in the unaffected part of the tooth, prevents 

 Nature from resorting to that process by which she 

 would otherwise cast off the dead matter. In con- 

 sequence of this, a foreign substance is retained for 

 a longer period, and at the same time disease is 



