37° 
CHEMISTRY OF THE DIGESTIVE PROCESSES. 
percentage of total solids and a correspondingly low specific gravity 
(1010). In the gall bladder absorption of water takes place, 1 and a 
mucin-like substance secreted by the epithelium of the gall bladder is 
added to it, so that it becomes viscid in consistency, the percentage of 
total solids is much increased, and the specific gravity rises (1030 to 1040). 
According to the time it stands in the gall bladder, these changes 
become more or less advanced, which accounts for much of the variation 
observed in the quantitative composition of different specimens of bile. 
The following table of analyses of dogs' bile, (a) from the gall bladder 
and (b) freshly secreted from a fistula, illustrates this difference : 2 — 
In a Hundred Parts by Weight of 
(a) Bile from Gall Bladder. 
(6) Freshly secreted Bile from 
a Fistula. 
I. 
II. 
I. 
II. 
Mucin ..... 
Alkaline taurocholates 
Cholesterin .... 
Lecithin ..... 
Fats 
Soaps 
Organic matter insoluble in\ 
alcohol ... J 
0-454 
11-959 
0-449 
2-692 
2-841 
3-155 
0-973 
0-245 
12-602 
0-133 
0-930 
0-083 
0-104 
0-274 
0-053 
3-460 
0-074 
0-118 
0-335 
0-127 
0-442 
0-170 
3-402 
0-049 
0-121 
0-239 
0-110 
0-543 
Bile is an alkaline fluid containing on an average - 2 per 1000 each of 
sodium carbonate and alkaline sodium phosphate. It has an intensely 
bitter taste, leaving a sweetish after-taste in the case of human or ox 
bile, but not in that of rabbit's or pig's bile. The bile of the ox and 
some other animals has a faint characteristic odour resembling musk, 
especially after warming. The colour is very variable : in carnivi ira it 
is usually golden-yellow ; in herbivora a grass -green ; but these colours 
are not constant, and vary with the amount of oxidation of the bile 
pigments ; the two chief colours are often mixed with brown, giving 
intermediate shades of yellowish and greenish brown. Human bile, 
when observed in a healthy condition and immediately after death, is 
often green, occasionally golden-yellow in colour. 
Bile contains no coagulable proteid, and remains clear on boiling ; it 
can also be diluted witli water without any turbidity arising. In human 
bile true mucin is present, 3 but the substance which gives viscidity to ox 
1 Accompanied by a selective absorption of inorganic constituents, so that the percentage 
of chlorides in gall bladder bile is even less than that in liver bile (Hammarsteu, loc. cit., 
sub. 15). 
2 Hoppe Sevier, " Lelirbuch der Physiol. Chem.," Berlin, 1881, S. 302. See also 
Hammarsten, Nova Acta. Reg. Soc. Sc. Upsala, 1893, Ser. 3, vol. xvi. ; Jahresb. u. d. 
Fortschr. d. Tkkr-Ckem., Wiesbaden, 1893, Bd. xxiii. S. 331. 
3 Hammarsten, Nova Acta R^g. Soc. Sc. Upsala, 1893, Ser. 3, vol. xvi. ; Jahresb. ii. d. 
Fortschr. d. Thier-Chcm., Wiesbaden, 1893, Bd. xxiii. S. 333. 
