THE LIVER. 1G7 



vein in resisting the action of water, and collecting in heaps 

 instead of numnmlar rows. It forms no spontaneous coagn- 

 lum, and only a small quantity of fibrin can be obtained 

 from it, even when whipped with rods. It has both a larger 

 proportion of corpuscles, and a larger amount of solid matter 

 in its serum than the portal blood; that is to say, it has less 

 water, as one might expect from the fact that the bile has a 

 much lower specific gravity than blood. The Solid residue 

 obtained by evaporation of its serum, contains a very de- 

 cidedly smaller amount of albumen than the solid substance 

 of the portal serum, a smaller amount of fat, and a large 

 increase in the amount both of salts and extractive matters. 

 "We must conclude, therefore, that albuminoids are decom- 

 posed in the liver, and that their decomposition gives rise to 

 the nitrogenous part of the additional extractive matters in 

 the hepatic vein. 



126. The student has now been put in possession of the prin- 

 cipal known facts which bear on the question of the use of 

 the liver in the economy, and it remains to consider what its 

 uses are. To do so, is to pass from the region of fact to that 

 of hypothesis, and it is well that the student should under- 

 stand how widely different these are, one from the other. It 

 is the deficiency in our knowledge of facts which necessitates 

 conjecture; were the chain of facts complete, the need for 

 conjecture would cease. 



Some points are beyond all doubt: the liver certainly 

 arrests fats and sugar, storing the latter up in the form of 

 glycogen. Whether it arrests other substances is not so 

 certain; but it cannot be denied that after death from arsenic 

 and other metals, the poison is found in particular abun- 

 dance in this viscus. It rids the blood of the colouring 

 matter which stains the serum coming from the spleen, 

 and it decomposes albuminoids, either on account of their 

 being in a condition unfit for circulation, or in overabun- 

 dance. The products of this decomposition are, it may be 

 supposed, nitrogenous extractive matters remaining in the 

 blood, and the bile removed from it; and it is quite possible 

 that glycogen, when present in the hepatic cells, may assist 

 the decomposition, though it is certain that bile is formed 

 when glycogen is absent from the liver. It has been pre- 



