Occasionally its characters are much more local, only affecting, for example, the calf of the leg ; and then the collateral circula tion prevents the serous exudation from being so distinct. Above the seat of swelling, pain may be traced for some distance in the course of the emergent vein, and when superficial, as in the ham or the groin, a distinct hard knotted cord may be readily felt vrith the finger, which persists long after the acute symptonas have subsided. The seizure is always a sudden one, and has no his tory beyond that of its being found in the associations indicated above.
Its common name of " white leg" sufficiently discriminates it from erythema nodosum or diffuse cellular inflammation, and its hardness and tension cannot lead to the mistake of supposing it to be mere muscular rheumatism. In some instances cedema with much tension, especially when one leg only is affected, presents characters of superficial tenderness not unlike phlegmasia dolens ; but it is always readily to be discriminated, by its commencing at the ankle, gradually extending upwards, and being always associated with venous congestion ; while the swelling of phlebitis begins in the fleshy part of the limb, and is never discolored by turgid bloodvessels.
A condition precisely similar may be sometimes seen in the arm, as a con sequence of bloodletting, when the lining membrane of the vein is irritated by the lancet, but it is usually associated with more or less of diffuse inflam mation.
§ 3. Capillary Phlebitis.—At: examinations some of the internal organs occasionally present appearances which have led t,o their being said to be the seat of capillary phlebitis. The name sufficiently indicates the nature of the lesion ; an exu dative inflammation attacking the interior of the capillary ves sels, and plugging them up with fibrin. It seldom passes to ves sels of large size. Its clinical history is unknown, and it is even difficult to conceive how, in the majority of instances, it could be discriminated by any signs during life from other inflammations of the same organ.
Phlebitis, ending in occlusion of vessels, will for a time interfere with the circulation through the organs in which the veins originate ; but their anasto mosis throughout the body is so extensive, that the obstacle is very soon over come by the blood being conveyed through some other channel. Tlie only case in which I have seen very serious, or, rather, fatal results, was one in which the inferior cava was obstructed, and nature was unable perfectlyto establish the circulation through the tortuous vessels. which, however, earned a very large portion of the blood from the lower extremities into the superior