i6 ON A NEW METHOD OF TREATING 



this fragment was so much covered up, that granulations were sprouting from 

 the medullary canal, showing that the bone was not dead in its entire thickness. 

 Nevertheless, as the superficial parts had certainly lost their vitality, I had not 

 doubted that a thin layer at least must exfohate from the whole. Now, how- 

 ever, I observed that some of the surface which remained exposed had assumed 

 a pink colour, implying that the layer of dead bone, whatever its thickness 

 might have originally been, had become so thin as to be transparent, through 

 absorption by new tissue growing in the interior. Further, on attempting to 

 pass the eyed end of a probe between the tibia and the granulations which had 

 enveloped it, I found to my surprise that the instrument could only be intro- 

 duced for a very short distance, the granulations, with the exception of a narrow 

 free border, being everywhere adherent. The new tissue outside the bone 

 had coalesced with that within, after complete absorption of the intervening 

 dead stratum. Hence the remarkable absence of discharge from around the 

 bone. 



During the following month I was absent from home, but was informed 

 that the same process was for some time continued : the granulations gradually 

 encroaching more and more on the exposed bone, and adhering to it as they 

 advanced. The upper fragment was thus entirely covered without any exfoha- 

 tion occurring, and the bare surface of the lower fragment was reduced to com- 

 paratively small dimensions. On the loth of September the remainder of the 

 dead part, being loose, was removed without difficulty as an exfoliation. It 

 was about an inch in greatest length ; but was of extremely irregular shape, 

 full a quarter of the circumference of the tibia being deficient. At the upper 

 end, where it had been most prominent and had become discoloured, it had 

 nearly the full thickness of the dense tissue ; but towards the lower end it 

 became thinned away, so as to be in some places as delicate as tissue-paper. 

 The outer surface presented near the margin an appearance of especial interest, 

 being at some parts, even where the bone had considerable thickness, variously 

 scooped and bevelled in a manner that admitted of no other explanation than 

 that the granulations overlapping the dead bone externally had been engaged 

 in its absorption. On applying a magnifier to these excavations in the external 

 surface, they were seen to present a peculiar velvety aspect, differing from the 

 rest of the exterior, but resembling the internal parts of the exfoliation. 



The only observation at all analogous to this with which I am acquainted 

 is that of the effects produced upon the ivory pegs used in Dieffenbach's method 

 of treating ununited fracture, the parts of the pegs driven into the bone having 

 been observed, when removed, to have suffered diminution in size. This has 

 hitherto remained as an isolated fact, and it has been regarded as an axiom in 



