270 ' Inflammation. 



which fresh cells constantly move into the dead structure, grow 

 all through it and break it down, bearing away particles of the 

 disintegrated material or any minute foreign elements (bacteria, 

 etc.), and in this way gradually removing tlie agents producing the 

 inflammation. 



These features have been studied experimentally in a variety 

 of ways. They may be easily observed by injecting into a tissue 

 an emulsion containing fine particles of carmine. An inflamma- 

 tion is determined in the course of which the leucocytes and fibro- 

 blasts become loaded with pigment granules, and giant cells are 

 formed which also englobe the pigment particles. Some of the 

 carmine is carried out of the area by the motile cells ; when larger 

 amounts have been introduced tlie parts which cannot be carried 

 away are encapsulated by the connective tissue cells and the cica- 

 tricial tissue arising from the latter. When porous foreign bodies 

 like bits of sponge or elder pith are introduced aseptically into the 

 subcutaneous tissue or into the peritoneum, at first the exuding 

 plasma and a large number of leucocytes occupy the spaces in the 

 substance, but later the connective tissue corpuscles and vascular 

 buds penetrate into them and take up all the available space (this 

 reactive proliferation is seen as early as the second day). 



After transformation into scar tissue (v. p. 241) the connective 

 tissue is found surrounding and filling all tlie spaces of the foreign 

 substance and isolating it from the rest of the organism (Ribbert). 

 Solid foreign material like silk thread, cat gut, silver wire, intro- 

 duced aseptically as sutures by surgeons, or bullets, needles, bits of 

 glass, w^ood splinters, or hairs which have gotten into wounds, pro- 

 vided they have no bacteria upon them and are truly aseptic for- 

 eign bodies in the tissue, are always surrounded by a wall of leu- 

 cocytes and proliferating connective tissue and thus encapsulated. 



The inflammatory reaction about a foreign body always depends 

 upon the soluble chemotactic substances which arise from the mate- 

 rial. About some bodies which give rise to but little substance of 

 this sort (aseptic cat-gut, silver wire) it may be very unimportant; 

 inflammation ceases entirely after these substances are completely 

 extracted from the foreign body, that is when it can no longer 

 give ofif soluble chemotactic material. The functional activity and 

 the movement of the cells mentioned toward the foreign matter can 

 be beautifully demonstrated, as pointed out by Ribbert. by inject- 

 ing liquefied agar or a blue-stained mass of gelatin into the sub- 

 cutaneous tissue or anterior chamber of the eye. Soon after the 

 jelly has hardened in the body it is surrounded by leucocytes and 



