1. The primary effect of a slight stimulus applied to the blood-vessels is a slight and gradual contraction, with a retardation of the current through them.
2. During this contraction, the blood is impeded, or altogether stops. But the vessels soon dilate to a size larger than they originally possessed, and the blood now Moves through them more rapidly than in the normal state. The slight stimulus that previously caused the vessels to contract, has now, if re-applied, little or no effect; but on applying a more powerful irritant, such as a minute drop of tincture of capsicum, the phenomena of active congestion or determination of blood become almost instan taneously developed. The vessels become lengthened, dilated, and tortuous, and are distended with blood which contains a great excess of red corpuscles, and is circulated with far more than the normal velocity.
3. But if the injury be still more severe—if, for example, a red-hot needle be inserted —then, in addition to the active congestion described in the preceding paragraph, there is a retardation, and finally a complete stagnation of the blood in the capillaries of the injured spot, while around it the blood moves rapidly through turgid but less full vessels.
The blood obtained by bleeding a patient suffering from inflammation of any impor tant organ, usually presents a peculiar appearance after coagulation. In healthy blood. the clot consists of a uniform admixture of blood corpuscles and coagulated fibriue, and is of a deep red color; but in inflammation, the upper part of the clot consists of a layer of a yellowish or whitish color, to which the term buff'/ coat is applied. This huffy coat is often concave, or hollowed out into a cup-like form, in which case the blood is said to be both buffed and cupped. The cause of this huffy coat is still to some extent an open question; but the phenomenon is clearly due to a subsidence of the blood cor puscles, by which a layer of fibrine, forming the huffy cdat, is left at the surface. Another and a more important change in the blood in inflammation is the augmentation of the fibrine, which often rises to two, three, or more times its normal quantity.
Reference has already been made to coagulable lymph or fibrine as one of the prod ucts of inflammation. This effusion of coagulable lymph is so important a process both for good and for evil, that a few lines must be devoted to its special consideration.
When coagulable lymph is effused between membranes that are normally in contact (or nearly so) with one another, it often causes them to cohere. In this way we often have adhesions of the adjacent surfaces of serous membranes, such as the Oeuvre, the pericardium, and the peritoneum, which materially interfere with the natural free motion of the parts, and occasion various persistent morbid symptoms. In inflammation of the
iris, the pupil may be rendered irregular or immovable, or may even be closed up by the effusion of coagulable lymph. In endoca•ditis, or inflammation of the lining mem• brane of the heart, coagulable lymph may be deposited in wart-like masses on the valves, and may thus occasion some of the worst forms of cardiac disease. On the other hand, in many cases, the effusion of coagulable lymph has a reparative and conservative influence. It is by the organization of this fluid that the lips of recent wounds are glued together, and that parts recently severed from the body may be sometimes replaced and still live. The success of the Talicotian operation, by which a new nose is engrafted in the position of that which had been lost—of the operation of injecting a stimulating fluid into cystic tumors, etc., with the view of setting up adhesive inflammation—and of various other surgical operations, essentially depends upon the property of organization possessed by this fluid. It is thus, too, that ulcers are grad ually filled up till the breach of texture is repaired.
The inflammatory diseases of the most important organs are described under their specific names, and, as a general rule, the termination itis is employed to indicate an inflammation. Thus, p]euritis signifies inflammation of the pleura; peritonitis, inflam mation of the peritoneum; iritis, inflammation of the iris; etc. Inflammation of the lungs, however, is usually known as pneumonia instead of pneumonitis.
It is unnecessary to enter into the consideration of the treatment of inflammation further than to remark (1) that if possible we must remove its exciting cause, which can seldom be done except when the inflammation is external; and (2) that thepatient should be placed on a strictly antiphlogistie regimen (which implies a total abstinence how solid animal food and stimulating drinks, clue attention to ventilation, temperature. etc.). Of the direct remedies, the most important (except in persons of weak or broken-clown constitutions) is blood-letting, although at present it is somewhat out of fashion. The medicines chiefly employed are purgatives, preparations of mercury, tartar emetic, and opium; while, as external applications, hot fomentations (octasionally cold lotions), and counter-irritation by means of blisters, sinapisms, setons, etc., are often of service.