BLADDER, NORMAL ANATOMY. 



376 



mon salt and taurin, which are to be separated, 

 and the latter purified a second by crystalli- 

 sation. Taurin, when purified, is in prismatic 

 crystals, neither acid nor alkaline, not altered 

 by exposure to air, inodorous, of a peculiar 

 taste : soluble in about fifteen parts of cold wa- 

 ter, and nearly insoluble in absolute alcohol : 

 it is fusible, and not decomposed by nitric acid. 



In concluding this subject, we must again 

 express our conviction that many of the sup- 

 posed proximate components of bile are pro- 

 ducts of the various operations and re-agents to 

 which it has been submitted, and that the ana- 

 lysis of Berzelius, which is the simplest, is 

 probably the most correct: from the uncertain 

 operation of various precipitants upon bile, and 

 from the facility with which the results vary, 

 apparently in consequence of very trifling causes, 

 there seems to be a peculiar tendency in its 

 component parts to undergo hitherto unex- 

 plained modifications. 



BILIARY CALCULI, or gull-stones. These 

 concretions have been especially examined by 

 Gren, Thenard, Fourcroy, and as to the fatty 

 matter which they contain, by Chevreul/* 

 Human gall - stones are, for the most 

 part, composed of a crystalline aggregate of a 

 species of adipocere, or as it has been termed 

 by Chevreul, cholesterine, (from p^oXn, bile, and 

 crregEo?, solid,) with more or less colouring 

 matter, muco-albumen, and inspissated bile ; 

 they are accordingly of various colours and 

 textures, but generally brittle and friable. 

 Those which are chiefly cholesterine, or as it 

 should more properly be termed cholestearine, 

 are white and crystalline, and lighter than 

 water; the others are more tough, coloured, 

 and dense ; their specific gravities, therefore, 

 vary from 0.803 to 1.06. Their chemical ex- 

 amination may be conducted as follows : they 

 may be powdered, and digested in water to 

 separate the inspissated bile : then boiled in 

 alcohol, and the solution filtered whilst hot ; 

 as it cools it deposits the cholesterine, and 

 often retains common fat and its acids in solu- 

 tion. The portion which resists the action of 

 alcohol may be digested in a weak solution of 

 caustic potash, which takes up colouring matter 

 and muco-albumen : the solution, supersatura- 

 ted by acetic acid, deposits these, and the co- 

 louring matter may afterwards be removed by 

 alcohol. Any common albumen may be de- 

 tected by ferrocyanate of potash added to the 

 acetic solution. 



Cholesterine separates in white pearly scales 

 from its hot alcoholic or etherial solution during 

 cooling; it fuses at about 280, raid when 

 heated to about 400, it sublimes : in the open 

 air it bums like wax. Its ultimate components 

 are 85 carbon, 12 hydrogen, 3 oxygen. It is 

 the most carbonaceous of all the varieties of fat. 



The gall-stones of the ox frequently consist 

 chiefly of the yellow colouring matter of the 

 bile, which is occasionally used by painters on 

 account of its brightness and durability : it is in- 

 soluble in water and alcohol, but readily solu- 

 ble in weak solution of potash, from which it 



* Annalcs <le Chimie, xcv. 5. 



is thrown down in green flocks by muriatic 

 acid : nitric acid cautiously dropped into a 

 solution of this colouring matter gives it various 

 shades of green, blue, and red. 



BIBLIOGRAPHY. Bianchi, Historia hepatica, 2 

 vol. 4to. Genev. 1725. Rcederer, Experimenta circa 

 bilis nat. 4to. Argent. 1767. Cadet, Exper. sur 

 la bile des homines et des animaux : Mem. de 

 1'Acad. de Paris, 1767. Bordenave, Analyse de 

 la bile, ibid, (Savans etrangers, t. vii.) Mm-liirf/, 

 Experiments upon the human bile, 8vo. Lond. 

 1772. Goldwitx, Neue Versuche zu cin wa'iren 

 Physiologic der Galle, 8vo. Bamb. 1782. Ploucquet, 

 Exper. circa vim bilis chyliferam, 4to. Tubing. 

 1792. Thenard, Deux mem. sur la bile : Mem. 

 d'Arcueil, t. i. Sannders, A treatise on the struc- 

 ture, &c. of the liver, 8vo. Loud. 1793. John, 

 Chemische Tab' lien : Tableaux chimiques, 4to. 

 Paris, 1816. Chevreul, Note sur la presence de 

 cholestcrine dans la bile de I'homme : Journ. de 

 Chim. Med. t. i. and Ann. de Chimie, No. xcv. 

 Bracconni.it, Rech. sur la bile : Ann. de Phys. ct 

 de Chimie, Oct. 1829. Orfila, Elem. de chimie, 

 2 vol. 8vo. Berzelius, Traite de chimie : Raspail, 

 Nouv. systeme de chimie organique, 8vo. Paris, 

 1833: Anglice a Henderson, 8vo. Lond. 1834. 



(W. T. Brande.) 



BLADDER, (in anatomy.) (Gr. 

 Lat. vesica, vesicula. Fr. vessie, vesicule. Germ. 

 Blase. Ital. vescicu). This term is employed 

 to denote a membranous sac, more or less 

 complicated in its structure, with one or more 

 orifices, and destined as a reservoir for parti- 

 cular fluids. We have, for instance, in most 

 animals provided with a liver, a gall-bladder 

 or reservoir for the bile ; in fishes we have a 

 swimming-bladder, vesica natatoria; and in 

 the females of several insects, mollusca and 

 crustaceans, a bladder, recently described by 

 Audouin, Milne Edwards, Des Hayes, and 

 others, the function of which is to receive, 

 during copulation, the prolific fluid from the 

 male, and which has, therefore, been called 

 vesicule copulutrice. In fine, in a great num- 

 ber of the animals provided with a urinary ap- 

 paratus we have a urinary bladder, vesica 

 urinaria. For a particular description of the 

 first three varieties of bladder we refer to the 

 articles LIVER, PISCES, and INSECT A.; that 

 of the urinary bladder forms the subject of the 

 succeeding article. 



(R. B. Todd.) 



BLADDER OF URINE (normal anato- 

 my). (KfcrTK ovfo^o^oi;, vesica urinnria. 

 Germ. Hurnblase. Commonly known as the 

 Bladder.) The urinary, like the biliary appa- 

 ratus, consists of four principal organs, each 

 accomplishing a different purpose, yet all con- 

 tributing to the same end, namely, the sepa- 

 ration from the circulating medium of a consi- 

 derable portion of aqueous and saline matter : 

 these are, first, the kidney or kidneys, which 

 are the principal, indeed the sole agents in 

 this function ; secondly, the ureters, the excre- 

 tory ducts, whose office it is to convey the 

 fluid secreted, drop by drop, as fast as it is 

 formed, which is by a slow and gradual pro- 

 cess, to, thirdly, the urinary bladder, which 

 serves merely as a temporary receptacle for it ; 

 and, fourthly, the urethra, or terminating ex- 



