Syphilitic Necrosis. 299 



c. "Where the chief changes are in the form of necrosis. 



6. 252. Syphilitic ("Mercurial") Disease of the Skull.— 



Portion of the left half of the skull-cap — macerated, illustrat- 

 ing the above. 



An irregular smooth patch in front of the parietal 

 eminence is almost entirely surrounded by irregular depressions, 

 which seem to be enlargements from dilated vascular channels. 

 Similar but less advanced stages of the' same process are seen 

 behind this large patch. On the inside a certain amount of 

 increased vascularity is traceable. The diploii is partially filled 

 up, and the bone as a whole is increased in Aveight. The cranial 

 sutures are nearly obliterated. F. P. C. 317. 



Presented by Professor John Thomson. 



6. 253. Syphilitic Disease of the Skull, advancing- to 



Necrosis. — Skull-cap of an old person — macerated, illustrating 

 the above. 



There are patches of roughened surface on the frontal and 

 parietal bones, but most marked on the right side, where the 

 opened-out vascular channels have been in many places enlarged 

 into irregular pits. Near the right parietal eminence irregular 

 trenches are marked out round portions of the bone. At one 

 place below, the trench communicates with the interior. On 

 the inside of the skull the bone shows enlarged vascular 

 channels all over, but most marked opposite the patches affected 

 on the outside. Xear the inner aspect of the right parietal 

 eminence the bone is almost entirely eaten through over an area 

 smaller than, but similar in shape to, that on the outside. 



B. C. I. 7. M. 12. 



6. 254. Syphilitic Disease of the Skull, with Necrosis.— 



Oblique section through ^the upper part of the vault of a skull — 

 macerated, illustrating the above. The bone has been trephined. 



