Bone Abscess. 245 



below iipwcards, apparently unconnected -with it. The integu- 

 ments were everywhere sound. On the anterior and somewhat 

 inner aspect of the limb a circular opening, rather more than 

 an inch in diameter, led into the interior of the bony case. 

 The integuments passed into the opening for a short way, 

 passing insensibly into a soft mucous-looking membrane lining 

 the whole interior of the osseous case, and seemingly occupying 

 the centre of the tibia. These facts were observed before any 

 dissection, on merely removing the plug mentioned in the case 

 above, which the patient used to insert and withdraw at 

 pleasure, so as to allow of the escape of matter and the washing 

 •out of the cavity. On dissecting the limb, these conjectures, 

 as far as they regarded the nature of the tumour, were found 

 to be correct. A section of the tibia in its long axis showed 

 the upper part of the tibia dilated into an enormous cavity, 

 -capacious enough to contain sixteen and a half ounces of fluid, 

 lined throughout by the membrane already spoken of, and 

 communicating externally by means of the aperture, which the 

 patient was in the habit of plugging up. The lower portion of 

 the tibia was quite sound, and scarcely, if at all, altered from 

 its natural appearance. The medullary cavity of this sound 

 portion did not communicate with the diseased cavity above, 

 -nor do the walls of the cavity itself present any very remarkable 

 or diseased appearance, and they are of considerable thickness. 

 Of the surrounding soft parts — muscles, nerves, arteries, etc. — it 

 juay be said that they were perfectly healthy. The muscles 

 which ran over the tumour were put greatly on the stretch, but 

 in all respects quite healthy. Indeed, the change affecting the 

 tibia was limited entirely to itself, nor did the periosteum 

 covering it show any diseased appearance or change of structure." 

 The following points may be noted on this macerated 

 portion. The inner wall of the cavity presents a surface 

 formed of opened-out, carious-looking bone, showing at some 

 places necrotic and almost loose portions, and at others irregu- 

 lar pockets, probably resulting from the separation of necrosed 

 fragments. The wall of the cavity, which varies from one- 



