DESTRUCTION OF BLOOD-CELLS IN THE LIVER. 209 



oxidation of the sugar, constantly formed by the liver, the accumulation 

 will make its appearance in the urine. The appearance of saccharine 

 matter in that secretion may be equally well attributed to its non-de- 

 struction in the system generally as to its over-production by the liver. 



This gland, besides producing sugar and fat, is the seat in which the 

 worn-out blood-cells are finally disintegrated, and probably Destruction O f 

 the young ones pushed forward through a certain stage of blood-cells in 

 their development ; advantage, moreover, being incidentally t 

 taken of the secreted bile, which possesses properties useful though not 

 essential for promoting the digestion and absorption of fatty material, 

 perhaps, also, of imparting a definite course to the transmutation of the 

 semi-digested material in the intestine, and this both as regards nitro- 

 genized ? amylaceous, and fatty bodies. Of the influence of the bile in 

 promoting the absorption of fat, the physical experiments which have 

 been alluded to leave no doubt; but that these uses are of a secondary 

 or non-essential kind, and are only taken advantage of in an indirectly eco- 

 nomical way, is established beyond all possibility of a doubt by the fact 

 that animals can live for a long time, even for months, without the pas- 

 sage of bile into the intestine, provision having been made for its escape 

 externally through an artificial fistulous orifice. 



These conclusions respecting the functions of the liver are in harmony 

 with the appearances presented by the blood leaving and entering it : 

 the predominance of colorless blood-cells, and of young cells well ad- 

 vanced toward perfection in the former, and of wasted, worn-out ones in 

 the latter ; with the fact that the maximum secretion of bile does not 

 take place until more than half a day after the ingestion of food ; and 

 that during foetal life, in which there is no food, either in the stomach or 

 intestine, to be digested, the liver is nevertheless in high activity, and 

 bile is secreted. 



In view of all the preceding facts, we may therefore finally conclude 

 that there are at least four distinct operations conducted in the liver; 1. 

 The production of sugar and fat ; 2. The separation of the bile ; 3. The 

 destruction of old blood-cells ; 4. The completion or perfection of young 

 blood-cells, perhaps by receiving their iron. With respect to these it 

 may be remarked, 



First. The formation of sugar and fat, either from carbohydrates, or 

 what, in this instance, is more probable, from albumenoid bod- General sum- 

 ies brought by the portal vein, can no longer be doubted. 

 The prevalence of liver-sugar and liver-fat in all that region er. 

 of the venous circulation included between the liver and the lungs must 

 be attributed to this source. That the sugar undergoes rapid metamor- 

 phosis in the pulmonary organs is plainly proved by the effects of irri- 

 tation of the pneumogastrics, which, interfering with the function of rcs- 



O 



