01- TIJE SHAFT OF A LONG BONK. 71 



The death of the entire shaft of a long bone must be a very 

 rare occurrence. In a case of this kind, the shaft would be 

 found lying loose in a cavity formed by the epiphysis at each end, 

 and the separated periosteum on the sides. The bone itself, al- 

 though its surface might be opened up by inflammation, would 

 present no ulceration or actual deficiency of substance. In a 

 case of this kind, I believe no regeneration whatever woidd take 

 place. The epiphysis have no tendency to assist ; and the perios- 

 teum has separated without a single portion of the shaft from 

 which new bone might be produced. 



In the majority of instances of what is incorrectly named death 

 of the entire shaft, ulcerated portions or deficiences of the surface 

 will be met with ; and in the periostea! sheath scales of new bone 

 corresponding to these will be perceived. I have observed the 

 process by which these ulcerations are produced, and have already 

 described it in the chapter on ulceration. 



The first appreciable inflammatory changes in bone occur with- 

 in the haversian canals. These passages dilate or become opened 

 up, as may be seen on the surface of an inflamed bone, or better 

 in a section. The result of this enlargement of the canals is the 

 conversion of the contiguous canals into one cavity, and the con- 

 sequent removal or absorption of ail the osseous texture of the 

 part. This removal of the substance of the walls of the haver- 

 sian canals is not to be explained by pressure arising from effused 

 lymph, understood either in a mechanical sense, which is inappli- 

 cable to actions of this kind, or in the Hunterian sense in which 

 it is employed, as a mode of expression for an action, the details 

 of which have not been recognised. 



By the enlargement of neighbouring haversian canals, and the 

 consecpient removal of all the osseous substance of a portion of 

 bone, an ulceration is produced, or a piece of dead or dying bone 

 is separated from the living organ. A stratum of what, in the 

 language of surgical pathologists, is named granulations, divides 

 the dead from the living, and ultimately casts the dead offj by 

 assuming a free surface towards it, throwing pus into the inter- 

 space. 



When the entire shaft of a bone is attacked by violent inflam- 

 mation, there is generally time before death of the bone takes 



