INTIMATE STRUCTURE AND FUNCTIONS OV THE LIVER. 29 



the vena porta to the hepatic vein, and rice versa. Wax, however, rarely passes, and 

 the hepatic duct is never filled either from the vena portee or -hepatic vein." 



From these facts M. Mappes is led to consider the granular substance to be the se- 

 creting part of the liver, around which the vessels are grouped as the conducting 1 and 

 preparatory apparatus. The more intimate connexion which it holds with the radicles 

 of the hepatic vein has induced him to presume that the bile is more probably separated 

 by it, from the blood which had actually arrived within these radicles, than from that 

 which circulates in the extreme ramifications of the vena portae. This particular sub- 

 stance appears also to M. M. to form the basis of all the glands, and to be of a peculiar 

 nature, modified according to the functions which nature has imposed on it. He fur- 

 ther supposes, that in all glandular structures there exists an intermediate substance, 

 between the extreme ramifications of both orders of vessels, which holds a more inti- 

 mate relation with the changes induced in the blood, than the other parts through which 

 it circulates. This substance he conceires to be of a mucous character, and to form the 

 basis of the granular part of the liver and other glands, in which the vessels terminate 

 and commence, and which, he thinks, is entirely appropriated to the particular function 

 and destination which the gland is intended to fulfil. In proof of this he quotes Dcellinger. 

 who has adopted a similar opinion. M. Mappes, in an analysis which he offers of Ey- 

 senhardt's investigations respecting the anatomy of the kidney, concludes that the inti- 

 mate structure of this organ and the liver is in many respects" similar. 



Although it is generally agreed amongst physiologists that the secretion of the bile 

 takes place in the granular structure of this visc'us, it is by no means so generally allowed 

 that the secretion is furnished by the blood of the vena portse. Bichat contended that 

 the bile is secreted from the hepatic artery, and adduced numerous analogies in support 

 of the opinion. More recently M. Magendie has considered it to be formed, at the 

 same time, from the blood of both the portal and arterial systems. 



It seems to us most probable, reasoning from the facts ascertained respecting absorp- 

 tion, that the blood which circulates in the vena portae, being that which is possessed 

 of the venous characters in the highest degree, and which, moreover, has a considera- 

 ble portion of new materials the products of digestion and absorption poured into it 

 before it reaches the liver, undergoes there those changes which are necesssary to a 

 perfect assimilation of these materials, and to the future offices which the blood itself 

 has to perform in the animal economy ; and that, in the course of, or in addition to, 

 these changes, the blood of the vena portce has certain of its elements eliminated from 

 it, the elimination of which is requisite not only to the accomplishment of these chan- 

 ges, but also to the production of a secretion which perform certain offices in the pro- 

 cess of digestion. This view of the subject is supported by the facts, 1st, that those 

 elements, of which the bile is composed, abound the most in the blood of the vena por- 

 tx, and that, if they were to remain in the blood circulating throughout the body, con- 

 sequences subversive of its healthy existence would rapidly supervene;--2d,that the por- 

 tal ramifications are plentifully supplied with the ganglial nerves, which we have shovvu 

 to be the source whence the blood-vessels derive their vitality and functions, and the 

 origin of those changes which the fluid circulating in them experiences ; and 3d, that 

 the divisions themselves of the vena portse, receive a much greater supply of arterial 

 capillaries from the arteria hepatica than is observed with respect to any other vein in 

 the body. 



From anatomical investigation, therefore, from numerous experiments bearing 1 in- 

 directly on the subject, and from pathological observation, we infer, that the blood 

 which returns from the digestive tube, from the spleen, &c. [having been shown to 

 contain a considerable portion of absorbed materials, some of them of a more or less 

 heterogeneous description, others of them more or less animalized ; and, moreover, that 

 certain of the elements or constituents of the blood, requiring to be eliminated from 

 the system, are there in an increased and hurtful quantity, if they were allowed to re- 

 main in it, undergoes in the liver most important changes ; that these changes are of 

 two kinds, the one referring to the assimilation of the less animalized materials which 

 the blood may contain, the other to the elimination of the heterogeneous, hurtful, or 

 effete elements which may circulate* in it ; that these are produced through the me- 

 dium of the vessels and granular structure of the liver, by the vital influence with which 

 both are endowed from the ganglial nerves supplying them ; that these changes are per- 

 fect or defective, in proportion as that influence is perfect or defective, provided that 

 the structure of the parts- the instruments of this influence, be not deranged ; and that 

 as the vital functions of the organ, depending upon the sources pointed out, may vary 

 very greatly; and, as the structure of one or more of the parts constituting the organ 

 may consequently become deranged, the operations of the liver may be thus disorded 

 :u a simnle o? more or less complex manner. 



