COMPOSITION OF JHE BILE. 405 



is usually stated at from 8 to 9J per cent. Of this solid matter, about a 

 tenth consists of alkaline and earthy salts, corresponding with those of 

 .he blood ; whilst the remainder is made up of organic constituents. 

 These are very readily decomposed, and enter into new combinations 

 with the substances employed to separate them; so that different 

 Chemists, by employing different means of analysis, have obtained re- 

 sults which seem far from conformable. All are agreed, however, that 

 the chief part of the solid ingredients of bile are allied to fat in compo- 

 sition ; consisting of a very large proportion of carbon and hydrogen, 

 and of a comparatively small amount of oxygen and azote. According 

 to Prof. Liebig, the organic portion of ox-bile may be represented by 

 the formula 76 Carbon, 66 Hydrogen, 22 Oxygen, and 2 Nitrogen, 

 with a considerable proportion of Sulphur. This substance, essentially 

 corresponding with the bilic acid, choleic acid, bilin, picromel, &c. of 

 different Chemists, seems to be a fatty acid ( 261), united with soda, so 

 as to constitute a soap. In healthy bile, the proportion of Cholesterine 

 appears to be very small, and it is held in solution by the preceding 

 ingredient ; but in many disordered states, and especially in disease of 

 the Gall-Bladder, this element is present in much larger amount ; and 

 it usually forms the principal, if not the sole ingredient in biliary con- 

 cretions. It is a white crystallizable fatty matter, somewhat resem- 

 bling spermaceti, free from taste and odour, and composed almost 

 entirely of carbon and hydrogen ; its formula is 36 Carbon, 32 Hydro- 

 gen, and 1 Oxygen. The Colouring matter of Bile is a substance 

 distinct from the preceding ; that of the Ox and other graminivorous 

 animals appears to be identical, or nearly so, with the chlorophyll of 

 the leaves on which they feed ; but that of Human bile seems to possess 

 different properties, and to be derived from the proper constituents of 

 the blood. 



725. Regarding the destination and purposes of this secretion in the 

 Animal economy, the following may be considered as a tolerably com- 

 plete summary ; though it is impossible to speak with precision on some 

 points, since the organic constituents of the Bile are liable to be so 

 easily altered by various reagents, that they are with difficulty recog- 

 nised. A portion of the Bile unquestionably passes off, in Man and 

 most other animals, with the faeces ; this portion, which includes the 

 colouring matter, is probably that which would be most injurious, if 

 retained in the blood, and is most purely excrtfnuntitious. In , bilious 

 diarrhoea, and under the influence of purgatives, especially mercurials, 

 a large quantity of bile is discharged per anum, apparently almost 

 unchanged. But in the healthy state, a portion, at least, of the soapy 

 compound seems destined for reabsorption. Just as ox-gall is com- 

 monly used to remove grease-spots, by its solvent power for fatty mat- 

 ter, so does the bile seem to act in the living body, by rendering soluble 

 the fatty matters of the food, and thus enabling them to be absorbed 

 by the lacteals ( 479). The fatty matter of the bile, when reabsorbed 

 with that of the newly-ingested food, is probably, like it, carried off by 

 the respiratory process : but it is easily shown, that the biliary matter 

 cannot supply more than one-sixth or one-eighth of the amount of 

 carbon eliminated from the lungs in the form of carbonic acid ; and 



