69 



There is pain in the thigh or ankle, followed in a few days by oedema. 

 The skin is of a dull white colour, as in phlegmasia dolens. 



Diagnosis. — It may be known by sudden pain and rapid oedema, 

 coming on in the latter stages of a chronic disease. 



Prognosis. — It is not dangerous in itself, but becomes a serious 

 complication in the latter stages of phthisis or cancer. If it termi- 

 nates favourably, the vein becomes again pervious by absorption of 

 the coagula, or the collaterals enlarge to carry on the circulation. 



Treatment. — Narcotics internally, and fomentations externally. 



39. Thus far, the committee have considered a few of those cases 

 in which the blood is diseased by a change in the relative proportion 

 of natural elements. Another source of disease, is the admixture 

 of foreign substances with the circulating fluids. "One of these," 

 says Stille (page 428), "is sugar, which has, however, been detected 

 in one disease only, diabetes mellitus. Pus is of more common oc- 

 currence in the circulating fluid, and is either generated within the 

 vessels or enters them from without." 



40. Pyohcemia. — Purulent Infection — Phlebitis. — Scdillot* 

 thinks, that in order to produce the symptoms usually attributed to 

 this disorder, the pus must be sanious or unhealthy, considering it to 

 depend on gangrenous liquefaction of the parts; and accounting for 

 the gangrene from strangulation caused by infiltration of pus. A 

 difference of opinion has existed, as to whence the pus comes which 

 is found in the veins. Some have supposed that it was derived from 

 the inflamed surfaces of the veins, others that it is a change of the 

 blood itself. In support of the former, Vogel's discovery of the 

 transition of epithelium cells into pus-globules, is cited as analogy; 

 and Henle's discovery, that the primary cell may be developed into 

 other forms either normal or anormal. Gendrin believes that the 

 changes from the blood-corpuscle into the pus-globule, may be seen 

 under the microscope, and Donne confirms him. Drs. Bennett and 

 Craigie mention two cases of purulent infectionf in connection with 

 disease of the spleen, where pus was formed in the blood independ- 

 ently of any local purulent collection. Dr. Budd, in his " Diseases of 

 the Liver" 1845, objects to the opinion that metastatic abscesses 

 are formed by pus, brought in the blood from the seat of the primary 

 suppuration and deposited in the new seat by a kind of aggregation, 



* Annales de Chirurgie. torn. 7. 



■f Edinburgh Medical and Surgical Journal, 1£45. 



