APPENDIX. (45) 



fcapula, begins now to be removed, from the Conftant preflure w.'^H'a"iiUoa. 



made upon it ; and before this, which we would call the fecond .. 



flate of the diflocation, is completed, that bone is refling on the 



furface of the fcapula itfelf. It is much to be wilhed, that it 



were afcertained, by accurate obfervatlons, when thefe changes 



take place, and particularly when the third Hate, which we are 



next to defcribe, begins. This laft ftate of a diflocation is, when 



nature is beginning to form a new joint to fupply the place of 



the old one. 



" The foft focket having been completely removed, the hu- 

 merus is refting on the furface of the fcapula. By prelFure, and 

 frequent motion, a cavity is formed for the head of the bone ; 

 the furface of this new cavity becomes fmooth, and is covered 

 with a cartilaginous cruft ; the attachment of the humerus to 

 the parts around anfwers the purpofe, and at laft affumes the ap- 

 pearance of a ligament, fo that a new joint may be faid to be 

 formed completely in all its parts. That this can happen, has 

 been proved by difledion ; and particularly in a man, after 

 whofe death my father had an opportunity of examining his 

 arm, which had been diflocated for upwards of thirty years. 

 This perfon was a fencing-mafter, and, as it was his right arm, 

 he was obliged to perform with it a great variety of motions. 

 He had acquired fo completely the ufe of it, that he could per- 

 form all the different motions neceflary in the fmall fword, ex- 

 cept pufhing a high carte *. 



•' Monfieur Moreau f gives two cafes fimilar to this, of old 

 luxations of the thigh, where the head of the femur had formed 

 a new acetabulum for itfelf in the os innominatum. Another 

 cafe, though not of a diflocated fhoulder, I fhall likewife de- 

 fcribe, 



• Mr Thomson diffefled a man with a new focket, formed in the infide of the 

 fcapula, Med. Obf. vol. 2. 



t Memoires de I'Academie de Cbirurgerie, tome v. p. 45. fimall edition. 



