26 DISEASES OF THE KIDNEY. 



sorption of liquid from the interstices of the tissues into the vessels is 

 more active, in proportion as the difference in concentration in the 

 liquid contained in the vessels and that without them is greater. 

 Now, as, in parenchymatous nephritis, this difference is abnormally 

 small, it follows, of course, that not only more liquid should leave the 

 vessels, but that less should return to them. I have observed cases 

 at my clinic which confirmed the correctness of this in the most strik- 

 ing manner. A girl, who had been suffering for a year from paren- 

 chymatous nephritis, stated that, some time before the appearance of 

 the oedema, she had felt exceedingly dull and miserable. Being con- 

 sidered plethoric, she was advised to get bled. A week after the 

 blood-letting, the first symptoms of anasarca- showed themselves, and 

 since then have never entirely disappeared. It may be inferred in this 

 case that the hydraemia, which, though extant in moderation, still had 

 not as yet produced dropsy, was so much aggravated by the blotfd- 

 letting as to cause the dropsical symptoms to appear. In another 

 case, the patient became anasarcous after a haemorrhage, but the ana- 

 sarca afterward disappeared for a while, and set in anew after the es- 

 tablishment of profuse suppuration. Nevertheless, hydraemia is not 

 the sole cause of Bright's disease, and probably not even its chief 

 cause. Dropsy, as severe as that seen in Bright's disease, is hardly 

 ever observed in any other form of hydraemia. It >ften occurs early, 

 but does not keep pace with the privation of the blood of its albumen. 

 The peculiar manner in which the oedema shifts from one region to 

 another is another argument against its dependence upon simple 

 hydraemia. If we abstract blood from an animal, and inject a corre- 

 sponding amount of water into its veins in its stead, the animal does 

 not become dropsical. Finally, the dropsy is so very often accompa- 

 nied by attacks of inflammation as to indicate that, besides, the thin- 

 ning of the blood, there is another source both of the transudation and 

 exudation, consisting in some disorder of the tissues as yet unknown 

 to us. 



It sometimes happens that the continual aggravation of the symp- 

 toms above described, and the excessive dropsy, which finally may in- 

 volve the serous sacs and alveoli of the lungs, cause death without 

 further complication. In most cases, however, remissions occur, in 

 which the condition of the patient improves, the albumen in the urine 

 diminishes, and the dropsy subsides. After a while he grows worse 

 again, perhaps once more to improve at a later period, and thus the 

 disease will fluctuate. In such protracted cases the above symptoms 

 are seldom the only ones, but are accompanied by others which arise 

 in part as complications of the main disease, and in part are immediate 

 consequences of it. 



