ANIMAL CHEMISTRY. 



trogen proceed from metamorphosed tissues, 

 then, if all the carbon of these tissues passed 

 into the bile, it would yield, at the utmost, 

 a quantity of bile corresponding to 7*15 oz. 

 of carbon. This is, however, far below the 

 quantity which, according to observation, is 

 secreted in this class of animals. 



44. Other substances, besides compounds 

 of proteine, must inevitably take part in the 

 formation of bile in the organism of the 

 herbivora ; and these substances can only be 

 the non-nitrogenized constituents of their 

 ibod. 



45. The sugar of bile of Gmelin (picromel 

 or biline of Berzelius,) which Berzelius con- 

 siders as the chief constituent of bile, while 

 Uema^ay assigns that place essentially to 

 choleic acid, burns, when heated in the air, 

 like resin, yields ammoniacal products, and 

 when treated with acids, yields taurine and 

 the products of the decomposition of choleic 

 acid; when acted on by alkalies, it yields 

 ammonia and cholic acid. At all events, 

 the sugar of bile contains nitrogen, and much 

 less oxygen than starch or sugar, but more 

 oxygen than the oily acids. When, in the 

 metamorphosis of sugar of bile or choleic 

 acid by alkalies, we cause the separation 

 of nitrogen, we obtain a crystallized acid, 

 very similar to the oily acids (cholic acid,) 

 and capable of forming with bases salts, 

 which have the general characters of soaps. 

 Nay, we may even consider the chief con- 

 b.. uents of the bile, sugar of bile and cho- 

 leic acid, as compounds of oily acids with 

 organic oxides, like the fat oils, and only 

 differing from these in containing no oxide 

 of glycerule. Choleic acid, for example, 

 may be viewed as a compound of choloidic 

 acid with allantoine and water: 



Choloid. acid. Allant. Water. Choleic acid. 



Or as a compound of cholic acid, urea, 

 and water : 



Cholic acid. Urea. Water. Choleic acid. 

 C 74 H 60 O 18 +C 2 N 2 H 4 O 2 -fH 2 O 2 =C 76 N 2 H 6 O 22 



46. If, in point of fact, as can hardly be 

 doubted, the elements of such substances as 

 starch, sugar, &,c., take part in the produc- 

 tion of bile in the organism of the herbivora, 

 there is nothing opposed to such a view in 

 the composition of the chief constituents 

 of bile, as far" as our knowledge at present 

 extends. 



If starch be the chief agent in this pro- 

 cess, it can happen in no other way but 

 this that, as when it passes into fat, a cer- 

 tain quantity of oxygen is separated from 

 the elements of the' starch, which, for the 

 same amount of carbon, (for 72 atoms,) con- 

 tains five times as much oxygen as choloidic 

 acid. 



Without the separation of oxygen from 

 the elements of starch, it is impossible to 

 conceive its conversion into bile; and this 

 separation being admitted, its conversion 

 into a compound intermediate in composition 

 between starch and fat offers no difficulty. 



4? . Not to render these cons iderations a 



mere idle play with formulae, and not to 

 lose sight of our chief object, we observe, 

 therefore, that the consideration of the 

 quantitative proportion of the bile secreted 

 in the herbivora leads to the following con- 

 clusions : 



The chief constituents of the bile of the 

 herbivora contain nitrogen, and this nitrogen 

 is derived from compounds of proteine. 



The bile of this class of animals contains 

 more carbon than corresponds to the quan- 

 tity of nitrogenized food taken, or to the por- 

 tion of tissue that has undergone metamor- 

 phosis in the vital process. 



A part of this carbon must, therefore, be 

 derived from the non-nitrogenized parts of 

 the food (starch, sugar, &,c. ;) and in order 

 to be converted into a nitrogenized consti- 

 tuent of bile, a part of the elements of these 

 bodies must necessarily have combined with 

 a nitrogenized compound derived from a 

 compound of proteine. 



In reference to this conclusion, it is quite 

 indifferent whether that compound of pro- 

 teine be derived from the food or from the 

 tissues of the body. 



48. It has very lately been stated by A. 

 Ure, that benzoic acid, when administered 

 internally, appears in the urine in the form 

 of hippuric acid. 



Should this observation be confirmed,* it 

 will acquire great physiological significance, 

 since it would plainly prove that the act of 

 transformation of the tissues in the animal 

 iody, under the influence of certain matters 

 taken in the food, assumes a new form with 

 respect to the products which are its result; 

 for hippuric acid contains the elements of 

 actate of urea, with the addition of those 

 of benzoic acid : 



1 at. urea . . C 2 N 2 H 4 O ? } 



1 at. lactic acid . . C 6 H 4 O 4 > 



2 at. benzoic acid . C 28 



2 at. chrystallized hippuric 

 acid 2 (C 18 NH 9 O 6 ) 



49. If we consider the act of transforma- 

 tion of the tissues in the herbivora as we 

 lave done in the carnivora, then the blood 

 of the former must yield, as the last products 

 of the metamorphosis, from all the organs 

 taken together, choleic acid, uric acid, and 

 ammonia (see p. 44 ;) and if we ascribe to the 

 uric acid an action similar to that of the 

 jenzoic acid in Ure's observation such, 

 namely, that the further transformation, 

 owing to the presence of this acid, assumes 

 another form, the elements of the uric acid 

 jeing incorporated in the final products it 

 will appear, for example, that 2 at. of pro- 



* The analysis of the crystals deposited from 

 the urine on the addition of muriatic acid has not 

 been performed. Besides, the statement of A. 

 Ure, that hippuric acid, dissolved in nitric acid, is 

 reddened by ammonia, is erroneous, and shows 

 that the crystals he obtained must have contained 

 uric acid. 



