114 THE ADRENALS AND THE RESPIRATORY BLOOD-CHANGES. 



Important in this connection is the close relationship be- 

 tween haamatoporphyrin and urobilin, formed when the former 

 is subjected to putrefactive conditions or nascent hydrogen, 

 which is present in very small amount in normal urine. This 

 pigment also occurs in fagcal matter, and is here recognized as 

 "stercobilin." In both urine and fasces, however, it appears 

 in excess, though apparently with no degree of parallelism, in 

 many morbid conditions. In acute fevers, for instance, it may 

 be increased to five or six times its normal ratio; especially 

 is this the case in pneumonia, typhoid fever, and the septic 

 fevers, in which rapid disintegration of the blood-elements 

 occurs. "In febrile disorders of almost every kind," says 

 Garrod, "temporary urobilinuria may be met with, the dura- 

 tion of which usually corresponds with that of the pyrexia. 

 In diseases of the liver, the urobilinuria is usually persistent, 

 as is well seen in cases of cirrhosis, malignant disease, or passive 

 congestion secondary to cardiac or pulmonary troubles. . . . 

 In diseases attended by excessive haemolysis, and during the 

 absorption of extravasated blood, there is apt to be conspicuous 

 urobilinuria, and, unless complications are present, there is no 

 corresponding increase of uroerythrin or haamatoporphyrin. 

 Such urines have a warm orange color, which is readily recog- 

 nized by a trained eye, and at the apex of a conical glass a 

 pinkish tinge is usually seen." He refers to the valuable diag- 

 nostic signs persistent urobilinuria affords in pernicious anae- 

 mia, as shown by Mott and Hunter, and to his personal ob- 

 servation that there is likewise a marked excess of urobilin in 

 the faaces. It follows hcemorrhages and especially intracranial 

 hcemorrhage, hsemorrhagic infarctions, pelvic haamatoceles, etc. 



The "chief seat of formation of urobilin is undoubtedly 

 the intestinal canal. This can only be gainsaid," says Garrod, 

 "by denying the identity of the urinary and faacal pigments." 

 (The identity of these is evident, and he refers to combustion 

 experiments conducted personally and with F. G. Hopkins, in 

 which this is confirmed.) Several investigators consider the 

 bile as the only source of urobilin. "There is strong evidence," 

 says Garrod, "that the urobilin in the bile itself is of intestinal 

 origin," while "it is equally clear that the substance from 

 which the intestinal urobilin is formed is the bile-pigment." 



