Jaundice, Icterus, the Yellows. 469 



3. Mineral poisons : phosphorus, mercury, copper, antimony, 



etc. 



4. Chloroform, ether, etc. 



5. Acute atrophy of the liver. 



II. Impaired or deranged innervation interfering with the 

 normal metamorphosis of bile. 



1 . Severe mental emotions : fright, anxiety, etc. 



2. Concussion of the brain. 



III. Deficient oxygenation of blood interfering with the nor- 

 mal metamorphosis of bile. 



IV. Excessive secretion of bile, more of which is absorbed 

 than can undergo the normal metamorphosis. 



Congestion of the liver : a. Mechanical, b. Active, c. Passive. 



V. Undue absorption of bile into the blood from habitual or 

 protracted constipation. 



Mechanical obstruction, by tying the bile ducts in a dog, 

 caused in two hours yellow coloration of the contents of the 

 hepatic lymphatics and thoracic duct, and also of the blood in the 

 hepatic veins (Saunders). That this jaundice is due to reab- 

 sorption and not to suppressed secretion of bile, already present 

 in the blood, may be fairly inferred, from the complete absence of 

 icterus, where, from general disease of the liver, the secretion of 

 bile has been entirely suspended, and in which the gall ducts and 

 bladder contain only a little gray mucus (Haspell, Frerichs, 

 Budd, Murchison), also from the fact that after complete extirpa- 

 tion of the liver in frogs not a trace of biliary acids nor pigment 

 can be detected in the blood, urine, or muscular tissue (Miiller, 

 Runde, Lehmann, Moleschott). Bile acids and bile pigment are 

 formed in the liver by disintegration of blood globules, and when 

 present in excess in the blood it is by virtue of reabsorption. 



This absorption will take place under the slightest favoring 

 influence. The obstructions in the bile duct, above referred to, 

 cause the tension in these ducts to exceed that of the blood in 

 the capillaries of the liver and at once osmosis of bile into the 

 blood vessels sets in. This may occur from so slight a cause as 

 the congestion and swelling of the duodenal mucosa around the 

 opening of the bile duct. Again, reabsorption of bile maybe de- 

 termined by a lessening of the normal fullness and tension of the 



