INFLAMMATION. 317 



serous membrane and the false membrane which covers it, is 

 operated by the few and feeble afferent and efiPerent vessels. At 

 a later period we find the state of things altered. The union 

 between the serous and the false membrane grows more intimate, 

 and finally becomes so close that any attempt to scrape or peel 

 the latter oflp Avould be futile ; the false membrane assuming the 

 character of an exceedingly intimate and wholly inseparable 

 bond of union between the opposed surfaces. The adhesion is 

 then complete. 



§ 272. The phenomena which manifest themselves when the 

 opposed walls of a serous sac are separated from the first by a 

 considerable amount of exuded fluid, and when this separation is 

 kept up for any length of time, are far more complicated. If we 

 consider adhesion, not only as a result of, but as the mode of 

 repair after inflammation, and in one sense as the goal towards 

 which every superficial inflammatory product tends, and on 

 arriving at which it may be regarded as mature, we must admit 

 that the means for attaining this end which are at the disposal 

 of the serous membranes, are far from being exhausted with 

 " primary " adhesion. They may unite not oidy by the first or 

 second, but by a third intention also. Of union by the first 

 intention I have already spoken ; the second mode is analogous 

 to the repair of wounds by the second intention, to organisation 

 after suppuration, with which we shall deal hereafter. 



Union by the third intention is peculiar to serous membranes ; 

 it stands between the other two. The surfaces which tend to 

 cohere are held asunder, not by pus or air, but by a fluid, 

 abnormal indeed as regards quantity, but differing in no essen- 

 tial qualitative character from that which is normally present in 

 the interior of a serous cavity. It has no irritating properties ; 

 but it hinders union, and gives room for very considerable pro- 

 liferation on the affected surfaces. The products thus formed 

 have their source, not in the epithelial layer, but in the 

 parenchymatous connective tissue of the serous membrane ; 

 looked at broadly, they present, as RokitansJd has alreadv 

 shown, the characters of a proliferation of embryonic tissue, of a 

 granulation. But I must not anticipate. 



§ 273. We are now entering upon the consideration of by 

 far the commonest variety of pleurisy and pericarditis ; it is 

 usually of rheumatic origin, and sets in with an abundant sero- 



