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INTESTINAL CHANGES BILE 



Changes in the Intestines. As already stated, the intestinal 

 secretions are alkaline, and in such a medium bacteria can readily 

 flourish. Bacteria therefore, are usually abundant after the food has 

 passed out of the range of the antiseptic gastric juice. Bacteria effect 

 various changes of a putrefactive character. Carbohydrates undergo 

 the lactic fermentation, cellulose is split up into carbon dioxide and 

 methane, while butyric acid and even free hydrogen are also produced. 

 In ruminants the amount of methane produced in these changes is 

 enormous. As much as 700 litres per day has been collected from a 

 fattening ox (Kellner). Other bacteria produce hydrolysis of fats, 

 yielding valeric acid, C 4 H 9 .COOH, or isobutyric acid, C 3 H 7 COOH = 

 CH(CH 3 ) 2 .COOH. 



Other microbes act upon the proteids, producing fatty acids and 

 amino-acids, also bodies of the aromatic series, of which indole, skatole, 

 tyrosine and phenol may be mentioned. 



Indole, C 6 H 4 



CH, is a crystalline substance melting at 



52, soluble in hot water, very soluble in alcohol or ether. It has a 

 peculiar odour and acts as a weak base. It is found associated with 

 skatole in faeces. It gives a characteristic red precipitate with nitric 

 acid. 



Skatole, methyl indole, C 6 H 4 : 



NH 



;CH, also a crystalline body, 



melts at 95. It is slightly soluble in water and readily soluble in 

 alcohol or ether. It, like indole, is volatile in steam and has a most 

 disagreeable faecal smell. With nitric acid it gives a white precipitate. 

 Phenol, C 6 H 5 OH, and Para-cresol, C 6 H 4 (CH 3 )OH, have also been 

 detected in faeces and result from bacterial action in the intestines. 



The Bile. This product is to be regarded both as a secretion and 

 an excretion of the liver. It is continuously poured into the intestines, 

 though the rate of its discharge varies with circumstances. A reserve 

 is usually stored in the gall bladder, with which many animals are 

 provided. 



According to a table given by Gamgee, the amount of bile and bile 

 solids (in grammes) secreted per 24 hours, per kilogram of body weight, 

 in the case of different animals is as follows : 



C 6 H 10 5 , which 



The liver is characterised by containing 



may be regarded as a reserve nutritive material. Its amount in the 

 liver varies considerably, being greatly increased after the consumption 



