INTRODUCTION. 35 



weak, quick, and often irregular, and the temperature 

 being liable to marked variations. This depends upon a 

 depraved condition of the blood in the majority of cases. 



Acute Inflammation is of the sthenic type, running its 

 course with well-marked symptoms, and passing rapidly 

 either to resolution or to suppuration, ulceration, or gan- 

 grene. 



In the CHRONIC form both local and general sym- 

 ptoms are slight ; the tendency is to firmness and organi- 

 sation of deposits with permanency of effects, and the 

 conditions which are set on foot by it are slow. Inflam- 

 mation is considerably influenced in its course and effects 

 by the tissue in which it is located; thus, we shall notice 

 that mucous membranes thus affected tend to suppurate, 

 fibrous tissues to undergo calcification, serous and 

 synovial to exudation of lymph, cartilage to caries and 

 ulceration, &c. 



Congestion is a form of diseased action, second, indeed, 

 to inflammation in importance and complexity, but never- 

 theless exercising an important influence upon pathology. 

 Dr. Williams distinguishes between congestion and 

 hypersemia, considering the former to differ from the 

 latter in that retardation of movement of blood through the 

 affected part has occurred. In both cases there is excess 

 of blood in the part, but in hyperaemia the flow is rapid 

 and the outfall as great as the income. Hypergemia is, 

 therefore, not disease ; it occurs in every organ or tissue 

 which is in a state of activity. Congestion may be active, 

 passive, or mechanical. 



Active Congestion is that accumulation of blood in a 

 part which occurs when the income is great but the out- 

 fall is small. It occurs as a result of irritation, precedes 

 the inflammatory process, and often is confused with 

 hyperasmia. 



Passive Congestion results from a relaxed condition of 

 the small arteries and the capillaries of a part depending 

 upon deficiency of tone, so the flow of blood becomes 

 slow, and the vessels distended. It may arise either from 

 local or general disorder of the vessels, from imperfect 



