INFLAMMATION. loi 



the process in one way or another. Furthermore, 

 because pathogenic agents differ so greatly in the 

 reactions which they excite, and different tissues re- 

 spond so variously to the same or different pathogenic 

 agents, we would be led into a description of every 

 form of inflammation, both acute and chronic — a 

 study that would not end until almost the whole domain 

 of pathological anatomy would have been explored. 

 But such is not our purpose. There are certain fun- 

 damental phenomena which characterize every inflam- 

 mation which, while they represent the primary reactions 

 to injury, are, at the same time, preliminary to repair. 

 These we propose to explain. Besides, the evolution 

 of inflammations in general presents special features 

 which permit us to point out the protean* character of 

 the process without committing us to a lengthy dis- 

 cussion. 



Four so-called cardinal symptoms of 

 Cardinal • n ^- i • i 



mnammation are commonly recomized, 

 Symptoms of . , , ,,. , . 



VIZ., heat, redness, swelhng and pam. 



,r*^,^.^ To these a fifth is added by some authors. 



MATION. , ^ ' 



interference with function. The phenom- 

 ena which underlie these symptoms are as follows: 

 Redness is due to a dilatation of the adjacent blood 

 vessels; swelling, to the increased calibre of the blood- 

 vessels, and to blood-serum and blood-cells which have 

 passed out from the walls of the former into the sur- 



* Assuming different forms. 



