188 PEINCIPLES OP VETEEINAEY SUEGEET 



yVhy is the definition of caries, "Molecular death of "honey 

 incorrect ? 

 According to recognized teachings of to-day the cell is tin 

 Tinit of life and not the molecule. Consequently, it is only i 

 cell or a group of cells "which can die, and not the molecule 

 Of course by the misnomer " molecular death" those employ 

 ing this faulty combination mean to say that death of a smal 

 portion of an organ has taken place. 



What forms of necrosis are of practical interest f 

 (1) Superficial, (2) deep. 



What is a sequestrum, f .] 



A piece of dead bone surrounded by living tissue. 



X>escr%be the process of sequestration in deep necrosis. 



A necrotic piece of bone is a foreign body and thus acts 

 as an irritant to the adjacent tissues, in this instance health j 

 osseous tissue surrounding it. Necrosis of bone and gangren« 

 of soft tissues are analogous; in a similar way as soft gangren^ 



; ous tissues are cast off soft healthy tissues by a line of granu- 

 lations, the so-called line of demarcation, a line of granulatior 

 springs up around and close to the necrosed bit of bone as th( 

 result of a granular osteitis. Now the salutory effect of i 



■ rarefying osteitis makes itself felt by dissolving and loosen 

 ing the dead piece of bone from the healthy bone, giving tb 

 necrotic piece at the same time a worm-eaten appearance upoi 

 its surface ; while this is going on an ossifying periostitis anc 

 osteomyelitis develop around the site occupied by the deac 

 piece of bone. Consequently new bone in the shape of aj 

 envelope forms, encasing the loosened piece of necrosed hone 

 This bony case containing the sequestrum and, of course, pus 

 is termed involucrum. This involucrum now is attacked bj 



