During the progress of au inflammation, when minute particles of foreign substances arc pres ent in the tissues, or where there is decomposi tion Of tissue elements, certain eells, derived probably mainly from the white blood-cells, make their appearance. These cells are known as `phagocytes,' and have the power of taking op these particle, of foreign matter or of disinte grated and either digesting them or carrying them off fur deposit at other points.
The healing of wounds is, in a pathological sense, an inflammatory process. If after a cut wound through tissues which have little vas cularity. the side, of the wound be closely ap proximated. there is a little oozing of serum which sticks the cut surfaces together, sonic of the more injured cells die and disintegrate, while of those wide)] remain intact sonic proliferate and cross the line of the wound. new connective tissue fibres are formed, and the firmly united. Such healing is known as healing by first intention. If the injury to the tissues is greater. or if the wound is left open. healing takes in a manner essentially the same as .just described, but somewhat more elaborate. Serum is poured out upon the surface of the wound and intermingled with the serum are led and white blood-cells. If bacteria are present pus is formed. After a varying length of time minute red points begin to stud the surface. These are known as granulations. Each granula tion consists of loops of minute capillaries sur rounded by newly formed connective-tissue cells. This tissue is called granulation tissue, and its now thin-walled vessels allow it to bleed easily. Over this granulation lissue—if the wound be not too large—the skin slowly extends by growth from the edges of the wound. until complete re pair takes place. Such healing is known as healing by granulation or healing by second intention. in some cases the growth of new blond vessels is in excess of the production of the connective tissue, and the tufts of new and easily Heeding, vessel, project above the surface of the Womul. These are known as exnberant granulations, or 'proud flesh.' Young granula tion tissue is composed almost entirely of small round or oval connective-tissue cells and blood vessels. the intercellular substance being very small in amount. As the tissue beeomes older the connective-tissue fibre; appear, the cells be come fewer and more like adult connective-I issue. eells. Finally the cells may almost entirely disappear, leaving dense White fibrous to \Odell the term 'cicatrix.' eicatricial tissue,' or 'sear tissu 0 is applied.
Under certain eonditions, whether due to increased nutrition of the parts or to some little-molerstood fact or we do not know, there occurs an active inerease in the eonnective-tissue elements of some of the organs of the body. This is known as productive inflammation. This pro duction or new connective or interstitial tissue may be slight in amount. It may, on the con
trary. be quite extensive. Its proliferation is always at the expense of the parenchyma or elements of the organ, and often results in eousiderable destruction of the latter. Not easily differentiated from this nrocluetive inflammation is the process known as replace ment connective-tissue hyperplasia. in which the formation of new tissue is secondary to degenera tion of the parenchyma and for the purpose of its replacement.
The significance of the inflammatory process and the relation which it bear, to the yormal Physiological activities of the hotly are n atters of extreme importance. If we exclude bacterial infection with the formation of pus and the pro duction of large amounts of fibrin. which oecurs in some cases—in other words. if we take such au example of inflammation as we studied in the exposed frog's mesentery—we note that all the phenomena observed arc but exaggerations of normal physiological processes. Thu, in nor nod physiological activity the relations existing between the blood inside the capillaries and the tissues outside are extremely intimate, and serum and white blood-cells, with probably some red blood-cell,. have more or less free aece,, to the tissues. The action of phagocytes also oc curs as a normal physiological process. We have referred to the pathological identity of wound repair and the inflammatory process. Suet' facts favor the consideration of inflammation, not as a destructive, but as a conservative process. a reaction which healthy tissue presents against external irritation. Even in the case of bac terial infection with the formation of pus, the inflammatory reaction is essentially conservative, the white blood-cells as distinctly germi cidal agents, destroying bacteria themselves by their phagocytie powers, and when dead disinte grating and diffusing their germicidal substances throughout the serum or pus. We must thus look upon the inflammatory reaction of tissues in the presenee of bacterial invasion as of the nature of a rising of the body forces for purposes of defense against the invasion.
While very convenient. inflammation is an objectionable and indefinable term. It has been suggested by Dr. A. II. Smith. of New York, to follow the nomenclature of which 'tuberculosis' is a universally accepted precedent. and give to the process resulting from the action of a 'nor agent in wounds and injuries the term Iramonsis.: to the process resulting from the local netion of poisons in the blood the loxosis:' and to the action and results of micro organisms the term imeteriosis.' The adoption of these suggestions would relieve us of our present nufortunate position of recognizing in ;lamination, instead of its cause, as an active process. and of allowing the inference that in flammation possesses a separate pathological energy.