SECRETION OF BILE. 631 



the Liver. If too much work be thrown upon this organ, its function becomes disordered, 

 from its inability to separate from the Blood, all that it should draw off: the injurious sub- 

 stances accumulate in the Blood, therefore, producing various symptoms that are known un- 

 der the general term of bilious. This is particularly liable to happen in warm climates, in 

 consequence of the diminished excretion through the Lungs, occasioned by the warmth of 

 the surrounding air, and the small quantity of exercise usually taken. To remove these 

 symptoms, medicines are required, which shall stimulate the liver to increased action. The 

 constant use of such, however,*has a very pernicious effect upon the constitution ; and care- 

 ful attention to the regulation of the diet, especially the avoidance of a superfluity of oily 

 or farinaceous matter, together with the employment of an increased amount of exercise, 

 will probably answer the same end in a much better manner. 



Besides the source of Biliary matter already pointed out in the decompo- 

 sition of the Fibrinous tissues ( 819), it seems probable that there is another 

 very important one in the continual waste of Nervous matter, which more 

 nearly approaches Bile in composition ( 249); especially if, as asserted by 

 Fremy, the peculiar acids of the Brain may be detected in the Liver. In 

 cases of slow Asphyxia, the amount of the Biliary secretion is much increased; 

 as might be expected, from what has just been stated of its purpose. 



837. It would not seem improbable, that the Liver acts towards the ab- 

 sorbed matters which enter the blood by the Mesenteric Veins, the same part 

 which the Lungs perform for those which are introduced through the Lymph- 

 atic system ; namely, the affording an opportunity for the excretion of super- 

 fluous or injurious substances contained in the absorbed fluid, before it 

 enters the general current of the Circulation. There is every reason to be- 

 lieve, that the conversion of Chyle into Blood is a slow process, requiring the 

 prolonged influence of the latter fluid upon the former; during this influence 

 many chemical changes take place, which are almost certain to be attended 

 with an extrication of Carbon and Hydrogen, these being the ingredients of 

 which the Chyle contains most when compared with blood ; and for the extrica- 

 tion of these, the Lungs and Liver afford ready means. Hence we see why the 

 Lacteal system should terminate in a Venous trunk near the Heart, so that the 

 fluid discharged by it will proceed at once to the Lungs ; and why the Liver, 

 wherever it has a distinct circulation, should receive the blood from the walls 

 of the Intestines. Among the Mollusca, in which the chyle is absorbed by 

 the mesenteric veins, (there being no separate lacteal system,) these veins, in- 

 stead of returning to the heart through the liver, terminate in the branchial 

 vessels ; and the process of depuration is effected by the gills. Their liver 

 is supplied only by the hepatic artery. 



a. This view derives interesting confirmation from the experiments of Cruveilhier, on 

 the artificial production of purulent deposits by injection of Mercury into the veins. He found 

 that, when the mercury was introduced into any part of the general venous system, abscesses 

 in the Lungs were induced ; each inclosing a globule, the irritation occasioned by which 

 was the cause of the purulent deposit. When the mercury was introduced into one of the 

 Intestinal veins, on the other hand, similar purulent deposits occurred in the Liver. It is 

 well known that abscesses in the Lungs and Liver are very common sequelse of wounds of 

 the head, and of surgical operations, especially those involving bones; and there seems good 

 reason to believe, that in such cases Pus (or some of its elements, which may act the part of 

 a. ferment in exciting suppuration elsewhere), is actually carried along with the current of blood 

 in the Lungs and Liver; and that, like the globules of mercury, not being susceptible of elimi- 

 nation by these two great emunctories, it acts as a disturbing cause, and occasions disease of 

 their tissue. The fact that a considerable amount of Copper may be detected in the substance 

 of the Liver, after the prolonged introduction of its salts into the system, seems to add weight 

 to this view of its function. It is yet to be ascertained, however, why some substances should 

 be arrested in this organ, whilst others are allowed to pass. 



