86 BILE. 



itself appears to derive considerable probability from anatomical 

 and physiological facts, and is certainly not refuted by our patho- 

 logical observations, we are necessarily induced to compare the 

 juices conveyed to the liver with those flowing from it ; since it is 

 only by a comparison between the fluids entering and leaving the 

 liver that we can hope to attain certain and fixed points of support 

 for a chemical survey of the mode in which the bile is prepared 

 from different organic elements, and thus avoid too wide a devia- 

 tion from the truth. If it be admitted that the portal vein mainly 

 supplies materials to the liver, we must seek in the blood of this 

 vein for the substances which contribute towards the formation of 

 bile ; and when the advanced state of our chemical knowledge 

 shall enable us to institute a comparison between the constitution 

 of the blood of the portal vein and that of the hepatic veins, it 

 will necessarily be the means of elucidating the mode of formation 

 of the bile and the function of the liver. 



Unfortunately, however, chemical analysis is not in a suffi- 

 ciently advanced state to afford a satisfactory reply to all, or even 

 to many of the questions which we hope to solve by its aid ; but 

 yet it affords us the means of confirming or refuting some of the 

 arguments advanced in support of one or the other of the above 

 views. As we purpose, in our remarks on " the blood/ 5 to enter 

 more explicitly into the consideration of the different parallel 

 analyses which we have made of the blood of the portal vein and 

 of the hepatic veins, we will limit ourselves in the present place to 

 a mere notice of the results in question. 



The comparison between these two kinds of blood is probably 

 more disturbed by deficiencies in our chemico-analytical appli- 

 ances, than either by the admixture of blood originating from the 

 hepatic artery with the blood of the hepatic veins, or by the 

 abstraction of materials by the lymphatics. As far as concerns 

 this addition of the blood of the hepatic arterial branches when 

 it becomes venous, this is very small ; for, independently of the 

 small calibre of the hepatic artery, which is far less than that 

 of the portal vein (a section of the hepatic artery is 4,909 square 

 lines, while that of the portal vein measures 38,484 square lines, 

 according to Krause and Valentin), the rapidity of the circulation 

 of the blood in the veins proceeding from the hepatic artery must be 

 nearly as small as in the equally large capillaries of the portal vein. 

 The lymphatics, however, appear chiefly to absorb the material 

 resulting from the nutrition of the vessels and the biliary ducts by 

 the hepatic artery, and to carry off some portion of the previously 



