INFLAMMATION. 309 



bowel, tends to compress it, wliile tlie other operates along its axis in a 

 direction opposite to that of the contractile wave. This movement is 

 aided by the recoil from the contents of the bowel as they are forced 

 downwards. The former element tends to bring the affected segment 

 into contact with an area of the parietal peritoneum directly propor- 

 tionate to the length of the mesentery of the affected segment (the 

 attached end of the mesentery acting as a fixed point). 



These considerations, into which I cannot enter more at length, 

 since they belong rather to the province of pathological physiology than 

 of morbid anatomy, indicate most clearly, that a perforation of the very 

 mobile small intestine is far more dangerous than one of the fixed 

 appendix vermiformis ; that a perforation of the stomach is more serious 

 when it occurs on its anterior aspect and on its greater curvature, than 

 when it is situated on the posterior surfiice and lesser curvature ; that a 

 pleurisy originating at the apex of the lung tends to remain circum- 

 scribed, while a pleurisy of the free border rapidly transgresses its 

 original limits, and so on. 



Inflammations of serous membranes are classified on the one 

 hand as acute and chronic, on the other as adhesive, suppurative 

 and indurative. As these varieties shade into one another by 

 infinite gradations, I prefer to adopt a mixed classification of a 

 more immediately practical character. 



§ 269. — Recent wjlaimnation. The epithelial layer is ob- 

 viously first exposed to the action of any irritant applied to the 

 surface of the membrane. Hence the earliest phenomena of 

 inflammation will naturally consist of changes in the epithelium. 

 Accordingly these changes, together with a simultaneous transu- 

 dation from the distended capillaries of the affected part, constitute 

 the first stage of every acute inflammation, and the anatomical 

 basis of what is shortly called a recent pleurisy, pericarditis, or 

 peritonitis. 



The serous membrane is reddened ; the hypera^mia of the 

 submucous capillaries is apparent even to the naked eye. That 

 the capillaries of the serous membrane itself are gorged with 

 blood and dilated, and that in consequence of this, the inter- 

 mediate islets of parenchyma seem smaller than usual, may be 

 demonstrated on any detached shred which is examined in 

 iodised serum under a low j^owcr. The surface at the same time 

 appears to have lost something of its natural polish ; this indi- 

 cates that the epithelium has become detached, and that the 

 emigration uf the colourless blood-corpuscles has already begun. 

 We notice a moderate amount of a reddish, soft and elastic sub- 



