COMPOSITION OF BILE. 369 



the secretion of the upper part of the small intestine is scanty in 

 quantity, slimy and clot-like, while in the lower part the secretion is 

 much more fluid, and contains small clot-like masses. It contains 

 4-5 parts per 1000 each of sodium chloride and sodium carbonate. 1 

 Pregl 2 has recently obtained succus enter icus from a Vella fistula in the 

 sheep, and estimated its alkalinity as equivalent to 0454 per cent, of 

 Na 2 C0 3 . The specific gravity of the fluid averaged 1-014. It contained 

 proteid, and coagulated on standing. Thiry found in the dog, 2 -2 to 2 '8 of 

 total solids, 07 to 1-2 of proteid, 07 to 0-9 of ash, per cent.; Leube, 0'8 to 27 

 per cent, of proteid; Quincke, 1/34 to 145 per cent, of total solids; 

 Frerichs, 2*27 per cent, of total solids; Gumilewski, 1-5 per cent, of 

 total solids. 



Tubby and Manning 3 obtained pure human succus entericus from a 

 piece of intestine, 3J in. in length, situated about 8 in. from the 

 ileo-caecal. valve, for a period of some months; the daily yield from this 

 length of gut averaged 27 c.c. (19 to 35). As a mean of thirty determina- 

 tions, the specific gravity was found to be 1-0069 (1-0016 to 1-0162). The 

 fluid was generally opalescent, and often had a brownish tint ; it con- 

 tained a few leucocytes and columnar cells, and was free from bacteria. 

 It was invariably alkaline in reaction, and gave off carbonic acid gas on 

 treatment with acids. It gave all the proteid reactions, and did not 

 reduce Fehling's solution or alter the colour of iodine solution. It con- 

 tained lactates, as shown by darkening a dilute solution of ferric chloride, 

 and giving Uffelmann's test. It also contained much mucin. 



BILE. 



Action on foodstuffs. Bile differs from the other digestive secre- 

 tions in not possessing a marked chemical action on any of the organic 

 foodstuffs. Bile alone is said to exert a diastatic action on starch, 4 but 

 this is very slight and inconstant, and seems to be merely due to a slight 

 absorption of diastatic enzymes ; 5 on the other foodstuffs it has no 

 chemical action whatever. Bile also increases the rate of action of 

 pancreatic diastase ; but the bile salts alone have a similar effect, so that 

 this accelerating action is not due to a diastatic enzyme. 6 



It has been shown that the presence of bile in the intestine 

 has a favourable influence on the absorption of fat, and that when 

 it is excluded, although the absorption of fat is not stopped, it be- 

 comes very defective, and the same amount -of fat cannot be taken 

 up as when bile is present. This will be considered later under Fat 

 Absorption. 



Chemical composition. In its physical characteristics and chemical 

 composition the bile is a variable mixture, not only in different classes of 

 animals, but in the same individual. As secreted by the liver cells, and 

 until it reaches the gall bladder, it is a clear limpid fluid, with a low 



1 Gumilewski, Arch. f. d. ges. Physiol., Bonn, 1886, Bd. xxxix. S. 565. 



2 Ibid., 1896, Bd. Ixi. S. 359. . 



3 Guy's Hosp. Rep., London, 1891, vol. xlviii. p. 277. 



4 Ewald, "Klinikd. Verdauungskrankheiten," 1890, Bd. i. S. 150. 



5 According to Kaufmann (Compt. rend. Soc. de. bioL, Paris, 1890, tome xli. p. 600), 

 the ferment occurs in the bile of the ox, pig, and sheep, in traces in that of the cat, and 

 never in dog's bile. Ellenberg and Hofmeister (Arch. f. wissensch. u. prakt. TMerh., 

 Berlin, 1885, Bd. xi. S. 381, 393) found a diastatic ferment in horse, ox, and sheep bile, and 

 occasionally in that of the dog and pig. In all cases, traces only of ferment are present. 



6 Martin and Williams, Proc. Roy. Soc. London, 1889, vol. xlv. p. 358. 



VOL. I. 24 



