Jaundice, Icterus, the Yellows. 471 



but is oxidized and decomposed in the blood so that it cannot be 

 detected, in blood or urine. But let the transformation be inter- 

 rupted, as in certain diseases of the lungs, with imperfect oxida- 

 tion, and the bile circulates in the blood, stains tissues and urine, 

 and in short causes jaundice. 



To sum up : it may be said that icterus is probably never due 

 to simple inactivity of the liver : it may, however, be caused by 

 excessive secretion of bile which is re-absorbed from obstructed 

 bile ducts or bowels : — it may result from imperfect transforma- 

 tion, in the blood, of the bile which is normally re-absorbed from 

 the intestine : or it may possibly be caused by the formation of 

 pigments in the blood from the abnormal transformation of bile 

 acids, or by solution of the haemoglobin of the blood corpuscles. 



The gravity of jaundice varies as much as its causes. It is 

 well known that the system may be saturated with bile, and the 

 tissues and urine deeply stained without much constitutional 

 disorder. The pigment alone is not an active poison. But there 

 may be much attendant suffering from obstructed biliary ducts or 

 bowels, from diseases of the lungs, or from disintegration of the 

 blood globules and imperfect nutrition, or there maybe profound 

 nervous prostration and disorder from uraemia, or from the pres- 

 ence in the blood of an excess of effete and partially oxidized 

 albuminoids (See Azotaemia). According to our present knowl- 

 edge, constitutional disorder, prostration and suffering in cases of 

 jaundice, are mainly due to the presence in the circulation of these 

 albuminoids, and of taurocholic acid which latter has a most 

 destructive effect on the blood corpuscles. 



The symptoms, therefore, are not characteristic apart from the 

 yellow coloration of the tissues and urine and the chemical 

 reactions of the bile acids and bile pigments furnished by the 

 latter. 



The coloration of the tissues may be a simple tinge of yellow 

 especially noticeable in the eye (conjunctiva), or it may amount 

 to the darkest shades of orange and brown. It may or may 

 not be complicated by the presence of spots or patches of blood- 

 staining (ecchymosis) on the visible mucous membranes but 

 especially in cases complicated by poisoning with taurocholic acid 

 or effete nitrogenous products. 



The urine may be similarly colored in all shades of yellow or 



