Etiology. Produced by irritants, whose character is to injure the tissues; influences of nervous system, etc.; mode of entrance of irritants. I. Principal phenomena, exhibited in an experiment. II. The state of the vessels, (Contraction not essential) dilatation with active hyperemia, followed by retardation; explanation of these; pavementing of veins. Increase of temperature, not due to heat production, but to excess of blood. III. The inflammatory exudation. (1) The serous and (2) the fibrinous exudation, (3) exudation of white corpuscles by emigration and of red by diapedesis, explanation of these; chemiotaxis; phagocytosis, (4) cells from other sources, (5) the purulent exudation, suppuration due to pyogenic microbes; the abscess; (croupous and diphtheritic exudations). IV. Changes in the tissues. (1) Parenchymatous changes; (2) New-formation of tissue, (a.) in the granulating wound; the formative cells and their origin: new-formation of bloodvessels and of epithelium; (b) other inflammatory new-formations. V. The issues of inflammation. VI. The forms of inflammation.

THIS is a subject whose importance in pathology can hardly be overestimated. From the time of John Hunter its phenomena have been taken as the basis of various speculations on the nature of patho logical phenomena in general. It is impossible to give a strictly accurate and complete Definition of inflammation. The oldest and still most generally received definition distinguishes it as characterized by the four cardinal signs, redness, swelling, heat, and pain (rubor, tumor, calm; dolor). These signs, however, by no means apply universally, and they are typical rather of the early stages of inflammation than of the later ones. Perhaps a definition which takes cognizance of the etiological character is least open to objection, and it may be said that inflammation comprises the ordinary phenomena which result from the action of agents which directly damage the living tissues.