176 



OF FOOD, AND THE DIGESTIVE PROCESS. 



mau at 3^ Ibs. daily, but such experiments have been shown by the Edin- 

 burgh Committee of the British Medical Association to afford uo reliable 

 data for comparative estimates, since the size and weight of the animals have 

 no^ relation to the amount of bile secreted. In one instance a large doo- 

 weighing 42 Ibs. secreted on an average only 1036 grains daily, while^a dog 

 weighing 11 Ibs. secreted 1857 grains daily. 1 Sc-hiff 2 has shown that a much 

 larger quantity of bile is discharged into the duodenum under normal con- 

 ditions than can be collected from a biliary fistula, the reason beiu<r that the 

 bile is reabsorbed with great rapidity, and is again excreted, together with 

 fresh bile, by the Hver. This observation has been confirmed by Laffcer, 3 

 under Heideuhaiu's direction, the evidence relied on being the injection of 

 bile into the duodenum, when its quantity was observed to be increased, and 

 the injection of colored bile or rhubarb into the intestine, which reappeared 

 in the course of a minute in that flowing from the canula. Wolf 4 found that 

 the amount of secretion in dogs was proportional to the size of the liver; 

 that it was more active in small and young animals ; that it was most abundant 

 on mixed diet (rising with the quantity of meat) ; less on a diet of bread or 

 rice, and least on a diet of fat ; and that it was greater by day than by night. 

 Wolf in Man and Arnold 5 in dogs found that the activity of the secretion 

 obtained its maximum an hour or two after food, Voit 6 two hours after, Kol- 

 liker and Miiller between the 6th and 8th hours, Bidder and Schmidt 7 about 

 10 or 12 hours after a full meal, and Dr. Austin Flint 8 from the 2d to the 

 8th hour. As Dr. Dulton has remarked, a distinction should be drawn be- 

 tween the time at which the largest quantity of bile is discharged into the 

 intestine, and that at which the secretory activity of the liver is at its height. 

 In his own experiments on a dog, which appear to have been conducted 

 with much care, a considerable quantity of bile was discharged into the in- 

 testine soon after feeding, as is shown in the following Table : 9 



The secretion diminishes considerably when food is withheld for some time; 

 the quantity poured out after ten days' starvation being only about one- 

 eighth of what it is when at its maximum. Still it is obvious, that although 



& 



1 See Report by Drs. Bennett, Rutherford, and Gamgec, in Trans, of British Assoc. 

 for the Advancement of Science, 1868. The experiments of this Committee, which' 

 was appointed for the purpose of determining the action of Mercury, etc., on the 

 Liver, showed conclusively that in dog, with biliary fistuhe the administration of 

 mercury does not cause any increase in the amount of bile secreted or discharged, 

 while if it, cause purgation or impairment of health, the quantity is diminished. 

 Neither Podophyllin and Taraxacum augmented the secretion. Purgation, how- 

 ever produced, invariably diminished the quantity. See also Brunton on Purgation 

 in Practitioner, 1874. 



2 Pfliiger's Archiv, 1870, p. 568. 3 See Laffter, lining. Dissert., Breslau 1873. 

 * Centralblntt, IHtl'.i, p. 86. * Zur Phys. der (ialle, Mannheim, 1854. 



Phys. ('hem Untersuchungen, Augsburg, 1857, p. 41. 

 Verdauungssafte und Stoffwechsel, gg 114-209. 

 Physiology of Mail. 1807, part ii, p.V;7"). 

 ' Dalton, Phys., 1871, p. 178. The clog in these experiments weighed 36 Ibs. 



