INTRODUCTION. 23 



Phlegmon or Inflammation is defined to be *■' perverted 

 nutrition of a part resulting from the application of a 

 stimulus not sufficiently powerful to cause immediate 

 death. ■'^ It is a familiar but complicated series of pheno- 

 mena of the highest pathological importance, since it occurs 

 in all tissues, and varies considerably according to its seat. 

 We may consider it is nature's method of rising to the 

 emergencies of injury, whereby repair is brought about. 

 In all cases it seems to follow injury of the part affected ; 

 thus it ensues in the majority of cases of wounds, and 

 originates in internal organs either as a result of local 

 injury, or when impressions made upon the surface of 

 the body have proved injurious to more deeply seated 

 parts through the intimate nervous unions which occur 

 between the structures. Of these nervous unions we are 

 not yet assured by physiologists. It cannot be expected, 

 therefore, that the pathologist will be in every case able 

 to determine how any cause which he suspects of having 

 originated internal inflammation acts. We accept this 

 theory of the nature of inflammation since it sufficiently 

 explains all the phenomena of that condition to afford us 

 a good practical basis. Inflamed parts are found to be the 

 seat of stagnation of blood in the vessels, of transudation 

 of its fluids with migration of its formed elements, also 

 of an altered condition of the tissue elements. Probably 

 the latter change is the most essential, for it is marked in 

 cartilage and other tissues which have only indirect blood 

 supply. It consists of high reproductive activity of these 

 cells { proliferation) J the products not being so highly 

 developed as the parent cells. The stagnant condition 

 of the blood in the vessels is brought about gradually 

 through certain stages. It is found, by observations of 

 the circulation in the blood-vessels of an artificially in- 

 flamed transparent membrane, that dilatation of the 

 vessels first occurs with acceleration of the flow of blood, 

 which, however, very soon becomes retarded, then irre- 

 gular and oscillatory until stagnation — " stasis " — ensues. 

 Then a large number of colourless corpuscles are found 

 to have accumulated in the affected vessels near the walls, 



