460 Veterinary Medicine. 



This reabsorptioa 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 capilaries of the liver and at once osmosis of bile into the 

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

 the congestion and swelling of the duodenal mucosa around the 

 opening of the bile duct. Again reabsorption of bile may be de- 

 termined by a lessening of the normal fullness and ten.sion of the 

 hepatic capillaries as when the aorta is mechanically compressed 

 by abscess, neoplasm, ingesta, or otherwi.se, j'u.st behind the dia- 

 phragm (Heidenham, Brunton). The cause is the same in both 

 cases, namely, the want of balance between the fullness and 

 tension of the bile ducts, and the hepatic blood vessels. There is 

 increased fullness of the hepatic biliary ducts, or decreased 

 plenitude of the hepatic capillaries and lymphatics. 



It must be added, however, that the coloring matter of the bile 

 is apparently produced, in the liver, from that of the blood, and 

 that the pigment (haematoidin), found in old extravasations of 

 blood, is probably identical with bilirubin, and that any agent 

 or condition which causes liberation of the coloring matter of the 

 red blood globules, will cause a staining of the tissues, like that 

 of jaundice. The following agents are known to have this 

 effect on the blood globules : water, in hydrosemic states of the 

 blood (Hermann) ; taurocholate of soda from ab.sorption of bile 

 (Frerichs, Kiihne, Feltz, Ritter) : chloroform (Chaumont) ; 

 ether (Burdon-Sanderson) ; freezing (Rollet) ; a high tempera- 

 ture + 60° C. (Schultze) ; frictional and induction currents of 

 electricity (Burdon-Sanderson) ; the alkalies (ammonia, potass 

 and .soda) and nitrites when present in excess. 



The injection of haemoglobin into the veins of dogs has been 

 followed by the appearance of bile pigment in the urine, but 

 Naumyn, Wolff, Legg and Brunton failed to obtain the same re- 

 sult in rabbits. 



It is noticeable that the haemoglobin of horses' blood is very 

 soluble at all temperatures and that of dogs very slightly so 

 (Burdon-Sanderson). This may serve to explain the great pre- 

 valence among solipeds of diseases, associated with dusky brown 

 or yellow discoloration of the muco.sse, with petechise, and with 

 the passage of blood pigments in the urine. It may further ex- 



