402 Theoretical Suggestions for the Improvement 



present instruments of surgery. They should likewise ob- 

 serve, with a professional eye, the various mechanieai im- 

 provements which are daily taking place. Might not the 

 circular saw be introduced in some operations ? Small cir- 

 cular saws, cutters, or wheels with toothed edges -of dif- 

 ferent sizes and thickness, might perhaps be used with ef- 

 fect in insulating and removing the depressed angular pieces 

 of bone which occur in fractures of the skull. When the 

 trephine is inadmissible, a circular cutter applied to the 

 edge of the fracture, might, if used with proper precaution, 

 cut away the bone with safety, and make a space sufficient 

 to admit the elevator. Such a cutter might be turned by 

 the hand, as great velocity would be dangerous. A method 

 could easily be contrived to apply such an instrument with 

 the requisite steadiness to the part. 



4th. The centre point of the trephine necessarily protrudes 

 beyond its teeth ; in consequence of which, when the inex- 

 perienced operator neglects too long to remove it, the most 

 serious effects are sure to follow. Might not this be easily 

 prevented by having a shoulder, as mechanics term it, to 

 surround the point, just so far down from the extremity of 

 the point, as to permit the saw to fix itself, and no more? 



5th. Would not a contrivance be useful, in trepanning 

 the skull, to fix the head in the most favourable posture? 



6lh. The best shape for the points of one description of 

 piercing instruments has, 1 think, never yet been exactly 

 ascertained; and it is certainly a question of considerable 

 importance. I mean those piercing instruments, where 

 breadth of instrument is requisite immediately on insertion ; 

 for, as to common needles, and other small instruments 

 merely for piercing, it is evident the more acute we make 

 their points, the better. In some instruments, however, 

 where a point is merely necessary for their insertion, when 

 that point is much prolonged beyond the efficient part of the 

 instrument, it becomes injurious: What point will suit such 

 an instrument best? Is it well ascertained that the drill or 

 shear point is the most advantageous ? Ft' the point formed 

 an acute angle, sloped to one side, would it not answer as 

 well? What is the proper angle for such a point? Me- 

 chanics pierce brass, copper, and steel with drills of different 

 shapes: May not ihere be an appropriate point for piercing 

 animal membranes ? The French discovered by experi- 

 ments (fatal experiments!) that the descending blade of the 

 guillotine cut best when sloped to a certain angle. How- 

 ever confident wc may be in our opinion, to experiment 

 we should always have recourse, whui possible; and in sa- 

 tisfying 



