414 Veterinary Medicine. 



most abundant one hour after feeding. It increases under a 

 copious and rapid blood supply, but is arrested by diminished 

 blood flow, even under increased pressure (in ligature of the vena 

 cava in front of the diaphragm). Vigorous exertion, drawing 

 off blood to the muscles of the trunk, diminishes the secretion of 

 bile, while transfusion of blood, up to a given grade of blood- 

 pressure increases it. Nervous conditions, which cause contrac- 

 tion of the portal vessels, increase the secretion by forcing more 

 blood through the liver. Such are strychnia or other stimulation 

 of the valve of Vieussens, of the inferior cervical ganglion, of the 

 hepatic or splanchnic nerves, or of the spinal cord. Fever causes 

 its arrest. 



The secretion of bile is further stimulated by the following : 



a. The ingestion of bile into the stomach and abdomen. This 

 being absorbed and carried to the liver greatly increases the 

 biliary .secretion. It is not necessary that the bile .shall be a pro- 

 duct of the same genus of animal, the bile of the ox is an active 

 stimulant of the liver of the dog. 



b. Of medicinal agents the following increase and liquefy the 

 bile : olive oil in large doses, phosphate of .soda, salol, and 

 salicylate of soda. 



c. The following not onl}' increase the bile, but through their 

 purgative operation, expel it from the bowels : calomel, mercuric 

 chloride, colocynth, aloes, jalap, rhubarb, podophyllin, and cold 

 rectal injections. These accordingly les.sen the .secretion later, by 

 removing the stimulus of the absorbed bile. 



d. The following are comparatively mild biliary stimulants : 

 benzoic acid, benzoate of soda, oil of turpentine, terpene, terpinol, 

 and euonymus, and still less active are alkaline bicarbonates, 

 bromides, sulphates and chlorides, ar.senic and ether. 



Secretion of bile is lessened by : starvation, a too fatty 

 dietary, alkaline iodides, atropia, strychina, hepatic degenera- 

 tions, (fatty, cirrhosis), catarrh of the bile ducts, diseases of the 

 liver, gall duct, or duodenum which interfere with the discharge 

 of bile, the antisepsis of the bowels, or the reabsorption of bile. 

 This work virtually moves in a vicious circle, as the action of 

 septic ferments in the duodenum hinders the reab.sorption of bile 

 and of the food products which go to the production of bile, and 

 in its turn the withholding of bile from the intestine removes the 



