374 



BILE. 



the thin ligament which connects this last with 

 the edge of the foramen magnum. Here we 

 find the nerve dividing into three branches for 

 these three muscles. 



On removing some cellular tissue from 

 between the recti majores, we observe the 



Rectus posticus minor, shaped like the last, 

 but much smaller. It arises close to its fellow 

 from a little tubercle on the back of the atlas, 

 passes upwards, outwards, and backwards, 

 to be inserted into the os occipitis between the 

 inferior oblique ridge and the foramen mag- 

 num. It is partly concealed by the rectus 

 major. This muscle can draw the head back- 

 wards. 



In quadrupeds these four muscles are pro- 

 portionally larger than in man. The inferior 

 oblique and the rectus major are considerably 

 larger. Birds have three recti, and only one 

 oblique the inferior. Reptiles and fishes 

 may be said to want them, as the analogy is 

 very remote. 



On removing the spinalis colli and all the 

 muscles of the fifth layer, we observe nume- 

 rous fasciculi of muscular fibres, which are 

 named inter-spinalis, inter-transversalis, and 

 multifidus spince. These might be considered 

 a seventh layer ; but they are very analogous 

 to the small muscles just described, and nearly 

 on the same plane. 



The inter-spinales are short bundles of fleshy 

 fibres placed between the spinous processes of 

 contiguous vertebrae. They are in pairs in the 

 neck, where the spine consists of two laminae. 

 Here also they are well marked. In the dorsal 

 region they are scarcely visible, and in the 

 loins they are not easily distinguished from an 

 interspinal ligament. They are analogous to 

 the recti postici. They extend the spine. 



On the lips of the spinous processes of the 

 neck some fibres may be shown, to which the 

 name supra-spinal muscles has been given. 

 They extend farther than from one vertebra to 

 the next. 



The inter-transversales are similar fibres, 

 scarcely to be demonstrated except in the neck, 

 where they are in pairs, corresponding to the 

 divided transverse processes. 



The multifidus spines consists of separate 

 bundles of fibres, extending from each trans- 

 verse process obliquely upwards and inwards 

 to the spinous process of the vertebra next above, 

 or sometimes to the second above. The first 

 bundle runs from the side or transverse process 

 of the sacrum to the spine of the last lumbar 

 vertebra ; the last from the transverse process 

 of the third cervical to the spine of the second. 

 They are smaller as we ascend, and are not 

 easily separated from the spinales and semi- 

 spinales. They support the spine, and rotate 

 one vertebra on the other slightly. 



In the article SPINE, the practical utility of a 

 knowledge of the muscles of this extensive 

 region will be demonstrated. 



For the BIBLIOGRAPHY of this article see that 

 of ANATOMY (INTRODUCTION). 



(Charles Benson.) 



BILE. Syn. Gall. (Gr.^oXTj; Lat. bills; 

 Fr. bile ; Ger. die Guile ; \\3\.jiele.j This im- 

 portant secretion has been laboriously examined 

 by several modern chemists of eminence, among 

 whom we may especially enumerate Thenard,* 

 Berzelius,f Tiedemann and Gmelin,J and 

 Frommherz and Gugert. Their results, how- 

 ever, are so much at variance, that it is impos- 

 sible to draw any general conclusions from 

 them respecting the real nature and chemical 

 components of the bile ; these discrepancies 

 seem partly to arise from the extreme facility 

 with which chemical agents react upon this 

 secretion, so that many of the supposed educts 

 or component parts which have been enume- 

 rated, are probably products of the different 

 operations to which it has been submitted, or 

 at all events modifications of its true proximate 

 elements : it has been therefore well observed 

 by Berzelius, that our present chemical know- 

 ledge of the nature of bile can only be consi- 

 dered as a foundation for the more extended 

 and satisfactory researches of future experimen- 

 talists. We shall here endeavour to select 

 some of the least disputable and most import- 

 ant facts respecting the chemical properties of 

 the bile, remarking at the outset to those who 

 may be inclined to repeat the experiments 

 which we shall cite, that the indications of re- 

 agents upon different specimens of bile are apt 

 to vary, and that their action is often much 

 modified by temperature, quantity, and the 

 mode in which they are used. 



There always appears to be mixed with bile 

 a variable proportion of mucus, probably deri- 

 ved from the gall-bladder and its ducts, and 

 not, therefore, a true component of the secre- 

 tion : this gives the bile its viscidity, and often 

 seems in some way to modify its other charac- 

 ters: in general, however, (ox-gall,) it is a 

 green liquid, varying much in tint, of a pecu- 

 liar odour, a bitter and nauseous taste, and a 

 specific gravity fluctuating between 1.020 and 

 1 .030. It does not coagulate when heated, and 

 although it may possibly contain albumen, or 

 something very like it, it is not immediately coa- 

 gulated by alcohol or by dilute acids. The rela- 

 tive proportion of solid matter obtained by evapo- 

 ration is between eight and ten per cent. By 

 means of acetic acid, the mucus which is mixed 

 with the bile may to a great extent be separated. 

 In the mammalia, generally, the bile exhibits 

 nearly the same characters ; and in birds and 

 fishes its components seem to be the same, but 

 rather more dilute in the former and more con- 

 centrated in the latter : it is always alcaline,from 

 the presence of soda, apparently in the same 

 state of combination as it exists in the serum 

 of the blood. When bile is evaporated very care- 

 fully to about half its bulk, and alcohol added, 

 (in the proportion of about four parts to one of 

 the evaporated bile,) a coagulated matter is 

 thrown down, which has some of the proper- 



* Thenard, Memoires d'Arcueil, i. 

 t Lehrbuch der Thierchemie. Dresden, 1831 ; 

 and Medico-Chirurgical Transactions, iii. 

 $ Uber die Verdauung (Essay on Digestion). 

 Schweigger's Journal, v. 1. 



