120 PHYSIOLOGY. 



Reabsorption of Bile=salts. 



When it was ascertained that the bile-salts were the products of 

 the hepatic cells, that only a small proportion appeared in the faeces, 

 with a still smaller proportion in the urine, the question arose: Is 

 the remainder reabsorbed by the intestines to be again secreted from 

 the blood by the hepatic cells? 



Bile-salts taken by the mouth produce an increased flow of the 

 bile, which is at the same time higher in its percentage of proteids. 

 Dog's bile, containing normally only taurocholate of sodium, has been 

 found to contain glycocholate, when that salt had been injected into 

 the animal's blood. Again, when bile has been taken from an animal 

 for some time by a fistula, its quantity of solids diminishes, showing 

 (that the hepatic cells cannot give back these salts to it when the portal 

 blood does not convey to them the materials for their formation. 

 From these and other facts it was deduced that there must exist in the 

 body reabsorption of bile-salts. 



Antitoxic Function of the Liver. It was found that nicotine 

 added to the portal blood of an experimental circulation through the 

 liver soon vanishes. Similar experiments with strychnine, morphine, 

 and quinine resulted in the same way. These alkaloids are not only 

 deposited in the liver-cells, but they experience a change in their 

 chemical constitution by which they lose their poisonous properties. 

 It is well known that the liver is a storage for the metallic poisons 

 mercury, arsenic, iodine, and antimony for long periods. The liver 

 also transforms the bodies developed by action of intestinal bacteria on 

 proteid. I refer to indol and phenol. Here the liver exerts a protec- 

 tive action against poisoning by these bodies. 



When the liver is removed, certain nervous symptoms supervene, 

 such as somnolence, ataxia, convulsions, and coma. This is supposed 

 to be due to the ammonia salts, generated in proteid digestion, get- 

 ting into the blood. When the liver is present, they are converted 

 into urea. 



The liver also reduces the toxic activity of poisons generated 

 by specific bacteria, as by the typhoid bacilli and tetanus organisms. 

 The liver is probably the seat of most active oxidations, and it is by 

 these chemical activities that it acts as a protective agent against 

 poisons. 



Internal Secretion of the Liver (Glycogen). Besides secreting 

 the bile to be partly used in digestion, but mainly as an excrementi- 

 tious substance, the liver possesses still another remarkable function, 



