APPENDIX. (47) 



wards replacing it, mud be to draw it out, fo as to bring it over v.-.'Hamiiio... 

 chat cavity out of which it was thrown. 



" This is to be done by making the extenfion of the arm, 

 with fuch a degree of force as to feparate the bones from each 

 other, and fo applied that it may aft only upon the parts round 

 the diflocated joint. When extenfion is omitted, as was the 

 cafe among the old furgeons, the attempts made by the lever to 

 force the humerus into its place, fo far from having falutary, 

 were attended with very bad, confequences. Extenfion, how- 

 ever, in the modern pradice, is our firfl view. The refiftance 

 to the exteniion is owing to the contraaion of the furrounding 

 mufcles, which is partly voluntary, and partly the effed of their 

 being much flretched, from the new fituation of the bone. The 

 firfl it is feldom in our power to prevent, as the terror of r^duo- 

 tion, and the uneafmefs confequent upon moving: the arm, 

 makes the patient exert his mufcles to refifl what gives him • 

 pain ; and fo far as no refolution in him can prevent this ac- 

 tion, it may be faid to be involuntary. Were it poffible to de- 

 ceive him, and make him fuppofe we were only examining the 

 flate of his arm, when we were really making the proper exten- 

 fion, this caufe of difficulty might be overcome in fome degree. 

 The refiftance from the overftretched mufcles is of more impor- 

 tance, as it is in our power to prevent it, and, when not attend- 

 ed to, muft increafe the furgeon's difficulty, and by extending 

 the mufcles, already too much on the ftretch, may produce 

 greater laceration than from the difeafe intended to be remedied. 

 " The obfervations we have already made on the ftate of the 

 mufcle after diflocation, muft now appear neceffary, being on a 

 fubjea little attended to, though of great importance, and par- 

 ticularly as they lead us to place our patient in fuch a manner 

 as to remove this caufe of difficulty and danger. 



« Another caufe preventing redudlion, is the bone being 

 pulled in fuch a direaion by the furgeon, as not to pafs through 



^ th£ 



