482 OF SECRETION AND EXCRETION. 



Lussana, 1 and others have demonstrated that a constant circulation of bile 

 takes place in healthy conditions, so that a large portion of that which has 

 been secreted by the liver and discharged into the intestines is reabsorbed 

 from thence and again separated by the liver. They found that on inserting 

 a canula into the gall-bladder after tying the ductus communis choledochus, 

 the discharge of Bile was considerable for the space of half an hour, the liver 

 during this period performing the part of a secreting as well as of an excret- 

 ing organ, but rapid diminution then took place in the amount discharged 

 from the canula, because Bile no longer entered, and could therefore no 

 longer be absorbed from the intestine. When, however, Bile was injected 

 into the blood, the quantity eliminated quickly underwent increase, though 

 it again diminished when the additional quantity had been excreted. The 

 cholagogue action of calomel appears to be in part due to its effecting a 

 diminution in the absolute quantity of Bile formed, as was shown by the 

 experiments of the Edinburgh Committee of the British Association ; 2 but 

 chiefly, as Dr. Brunton 3 maintains, to its stimulating action on the duodenum, 

 which causes the rapid transmission of the Bile through this portion of the 

 intestine; and if it be combined with sulphate of magnesia, or other saline 

 purgative, it is rapidly expelled from the system ; so that the reabsorption of 

 the excessive quantity resulting from too free living is effectually prevented, 

 and the "biliousness" so often complained of is temporarily, at least, removed. 

 [Rutherford and Vignal in experimenting with calomel on dogs state that it 

 diminished the biliary secretion in three cases, and slightly increased it in one.] 4 



395. In regard to the influence of the Nervous system on the secretion of 

 Bile, the results of experiments are contradictory : thus, whilst Pfliiger states 

 that no effect is produced on the secretion in regard to its quantity, at least 

 by section of the Pneumogastrics, Phreuics, Splanchuics, or Sympa- 

 thetic?, by destruction of the Coeliac Plexus, nor after destruction of all the 

 nerves entering the Porta Hepatis, provided the supply of blood be not in- 

 terfered with, Pvo'hrig 5 found that section of the splanchnics or of the spinal 

 cord, either of which causes dilatation of the abdominal vessels, is followed 

 by increased flow of Bile, whilst on the contrary reflex irritation of the cord 

 (as by stimulating a sensory nerve) by contracting the vessels, diminishes it. 

 The reason of this is that the most important factor in the secretion of Bile 

 is the rapidity of the circulation through the vessels of the abdominal vis- 

 cera. Irritation of the Spinal Cord is without effect if the splauchuics have 

 been previously divided. 6 



396. But besides the secretion of Bile, it appears that another purpose is 

 fulfilled by the Liver the production of an amyloid substance termed Gly- 

 cogen ; and we shall now proceed to consider the chief facts which have 

 been ascertained in reference to this so-called " Glycogenic function of the 

 Liver." It had long been well known that Vegetables were capable of pro- 

 ducing Starch and Sugar from the inorganic materials of their food, but the 

 presence of the former as a constituent of the animal body, in the test of one 



1 Lussana, Lo Sperirnentale, t. xxix, p. 337. See also Brit. Mod. Journal, January 

 4th, 1873. Kohrig, loc. fit. 



2 SIM- Transactions of British Association for the Advancement of Science for 1808, 

 p. 214, and Bennett's Text-Book of Physiology, 1872, p. 253. These experiments 

 fcinijily showed that the liver formed less hile. 



3 Brunton, in Practitioner, 1874, p. 412. 



4 [English Jour, of Physiology, Oct. 1875. Eeprintcd in Boston Med. and Surg. 

 Journal, March 10th, 1870.] 



5 Strieker's Jahrbucher, 1873. 



6 See Ilcidenhain, Centralblatt, 1807, p. 062, and 1808, p. 710; and Munk, Pflii- 

 ger's Arehiv, 15d. viii, p 151, who think that there is a primary increased How of bile 

 on irritation of the spinal cord, which is due to the contraction of the muscular 

 fibres they believe to be present in the biliary ducts. 



