570 LECTURE XXIV. 



The fact that under certain conditions a compound may be formed from 

 the blood-pigment in the tissues which is very similar to the bile-pigment 

 is proved by the discovery of hematoidin. Whether under normal con- 

 ditions such products are formed in organs other than the liver remains 

 undecided. In pigeons it has been found that after ligating the bile-duct, 

 the bile-pigments are found at the end of five hours in the blood-serum. 

 If at the same time the blood-vessels of the liver are also bound, the bile- 

 pigments cannot be detected in the blood nor in the tissues after several 

 hours. 1 Minkowski and Naunyn 2 arrived at the same result. They 

 extirpated the liver from a goose, and exposed this goose together with a 

 normal one to the action of arseniureted hydrogen. Whereas the latter 

 showed within a short time a copious elimination of urine containing 

 biliverdin, with the former only hemoglobin was found in the urine. 

 Such experiments have not yet been carried out with mammals on account 

 of the great difficulty in completely extirpating the liver from them. We 

 may safely assume, that with them also the liver is the sole place where 

 the bile-pigment is formed. 



For quite a time this assumption was doubted. It had been observed 

 that if for any reason the flow of bile to the intestines was prevented, 

 bile-pigments would appear in the tissues. There is a yellowish coloration 

 of the skin and of the mucous membrane. The complex of symptoms 

 which are produced when there is such a stoppage in the flow of the bile, 

 is known as icterus, or jaundice. Formerly there was a distinction made 

 between icterus of the above-mentioned etiology, also designated as 

 hepatogenic icterus, and hematogenic icterus. The reason for this was 

 because it had been observed that when for any reason there was an 

 increased destruction of blood-pigment, whether due to the action of 

 poisons (arseniureted hydrogen, ether, chloroform, toluylene-diamine) or 

 by infectious diseases, then bile-pigment passed into the urine even 

 when the flow of bile into the intestines was unrestricted. It was easy to 

 imagine from this that in such cases the blood-pigment was directly 

 transformed while in the blood-vessels into bile-pigment. It is not 

 necessary, however, to make any such assumption. The fact has been 

 established that intravenous injection of bilirubin causes a considerable 

 increase in the elimination of bile-pigment in the bile. 3 This observation 

 indicates that the liver also can cause the elimination of bile-pigment, 

 even when it is circulating in the blood-vessels. Now it is possible 

 that when there is a greatly increased disintegration of the blood 

 it may eventually contain so much hemoglobin, and finally so much 



1 Hans Stern: Arch, exper. Path. Pharm. 19, 39 and 42 (1885). 



2 Ibid. 21, 1 (7) (1886). 



3 J. F. Tarchanoff: Pfliiger's Arch. 9, 53 (1874). A. Vossius: Arch, exper. Path. 

 Pharm. 11, 427 (1879). 



