OPEEATIONS. 97 



placed a rasp in the mouth, which the animals attempted to 

 displace by movements of the jaws, not altogether insuffi- 

 c ient for the removal of asperities which injured the mucous 

 membrane of the mouth, and interfered with mastication. 

 T/he guarded rasp shown at Fig. 49, is employed frequently 

 o lower the sharp edges of teeth in old horses' mouths, 

 but where the prominences of teeth are very considerable, 

 Brogniez's system, called by him ' odontritia,' is the best. 

 Brogniez, for long Principal of the Belgian veterinary school, 

 was a man of great ingenuity, and to supersede the rasp and 

 other coarse instruments, he devised his ' rabot-odontriteur.' 

 This instrument, represented by Fig. 50, is composed of an 

 iron rod 3 feet in length, with a curved frame at one end, 

 in the middle of which a steel plate, sharp on both edges, is 

 fixed. The handle is of some weight, and, by fixing the 

 sharp prominences in the spaces before and behind the cut- 

 ting plate by slight taps, projections are knocked off 



Brogniez constructed another instrument, ' eiseau-odontri- 

 teur (Fig. 51), to knock off projecting portions of molar 

 teeth, and this instrument has been ingeniously modified by 

 Mr Gowing, whose dental sliding chisel is the most efficient 

 and satisfactory instrument that can be used for such morbid 

 conditions of the teeth. It is represented at Fig. 52, and Mr 

 Gowing says, it " consists of a cylindrical tube, which is at- 

 tached to a guarded frame with an opposing or cutting chisel 

 at the extremity so placed as to receive the concussion, so that 

 when the working chisel is struck, it prevents the shock from 

 being felt or sustained by the posterior teeth. The active 

 chisel, as you perceive, moves in the cylindrical tube which 

 forms the handle, the cutting part of it being guarded and 

 protected by the frame of which I have spoken. The round 

 part of the chisel plays or works through the cylinder, and 

 to it is attached a steel head or button for the receiving of 



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