CONSTITUENTS OF THE BILE. 411 



blood, according to HEDEXius, 1 by precipitating the proteins with alcohol, 

 filtering and acidifying the filtrate with hydrochloric or sulphuric acid, 

 and boiling. The liquid becomes of a greenish color. Serum and serous 

 fluids may be boiled directly with a little acid after the addition of alcohol. 



Besides the bile-acids and the bile-pigments, there occur in the bile 

 also cholesterin, lecithin, jecorin or other phosphatides (HAMMARSTEN), 

 palmitin, stearin, olein, myristic acid (LASSAR-COHN 2 ), soaps, ethereal 

 sulphuric acids, conjugated glucuronates, diastatic and proteolytic enzymes. 

 Choline and glycerophosphoric acid, when they are present, may be con- 

 sidered as decomposition products of lecithin. Urea occurs, though 

 only in traces, as a physiological constituent of human, ox, and dog bile. 

 Urea occurs in the bile of the shark and ray in such large quantities that 

 it forms one of the chief constituents of the bile. 3 The mineral constituents 

 of the bile are, besides the alkalies, to which the bile-acids are united, 

 sodium and potassium chloride, calcium and magnesium phosphate, and 

 iron 0.04-0.115 p. m. in human bile, chiefly combined with phosphoric 

 acid (YouxG 4 ) . Traces of copper are habitually present, and traces 

 of zinc are often found. Sulphates are entirely absent, or occur only 

 in very small amounts. 



The quantity of iron in the bile varies greatly. According to Novi 

 it is dependent upon the kind of food, and in. dogs it is lowest with a bread 

 diet and highest with a meat diet. According to DASTRE this is not the 

 case. The quantity of iron in the bile varies even though a constant 

 diet is maintained, and the variation is dependent upon the formation 

 and destruction of blood. According to BECCARI 5 the iron does not 

 disappear from the bile in inanition, and the percentage shows no con- 

 stant diminution. The question as to the extent of elimination by the 

 bile of the iron introduced into the body has received various answers. 

 There is no doubt that the liver has the property of collecting and retain- 

 ing iron, as well as other metals, from the blood. Certain investigators, 

 such as Novi and KUNKEL, are of the opinion that the iron introduced 

 and transitorily retained in the liver is eliminated by the bile, while 

 others, such as HAMBURGER, GOTTLIEB, and ANSELM, S deny any such 

 elimination of iron bv the bile. 



1 Upsala Lakaref. Forh., 29, and Maly's Jahresber., 24. 



2 Zeitschr. f. physiol. Chem., 1"; Hammarsten, ibid., 32, 36 and 43. 



3 Hammarsten, ibid., 24. 



4 Journ. of Anat. and Physiol., 5, 158. 



6 Novi, see Maly's Jahresber., 20; Dastre, Arch, de Physiol. (5), 3; Beccari, Arch. 

 ital. de Biol., 28. 



5 Kunkel, Pfliiger's Arch., 14; Hamburger, Zeitschr. f. physiol. Chem., 2 and 4; 

 Gottlieb, ibid., 15; Anselm, " Ueber die Eisenausscheidung der Galle, " Inaug.-Diss. 

 Dorpat, 1891. See also the works cited in footnote 1. p. 322. 



