108 PHYSIOLOGICAL CHEMISTRY. 



The Constitution of the Blood in different Vascular Regions and 

 under different Physiological Conditions. 



Arterial and Venous Blood. The most striking difference be- 

 tween these two kinds of blood is the variation in color caused by 

 their containing different amounts of gas and different amounts of 

 oxyhsemoglobin and haemoglobin. The arterial blood is light red ; 

 the venous blood is dark red, dichroitic, greenish by transmitted 

 light through thin layers. The arterial coagulates more quickly 

 than the venous blood. The latter, on account of the transudation 

 which takes place in the capillaries, is somewhat poorer in water 

 but richer in blood -corpuscles and haemoglobin than the arterial 

 blood (HEIDENHAIN, NASSE, OTTO). The quantity of sugar is 

 somewhat greater in the arterial blood than in the venous (OTTO). 



Blood from the Portal Vein and the Hepatic Vein. The blood of 

 the hepatic vein is poorer in ordinary red blood-corpuscles but richer 

 in colorless and so-called young red blood-corpuscles. A few investi- 

 gators have decided from this that a formation of red blood-corpus- 

 cles takes place in the liver, while others claim that a destruction 

 takes place. 



In consideration of the relationship to the simultaneous forma- 

 tion of small quantities of bile and lymph in the unit of time of 

 the large quantities of blood circulating throuhg the liver we can 

 hardly expect to detect a positive difference in the constitution of 

 the blood of the hepatic vein by chemical analysis. The statements 

 in regard to such a difference are in fact contradictory. For 

 example, DROSDOFF has found more haemoglobin in the hepatic 

 than in the portal veins, while OTTO found less. In regard to the 

 different amounts of sugar in these two kinds of blood we have 

 also much contradiction. According to a few experimenters, as 

 OTTO and above all others SEEGEN, the blood of the hepatic vein is 

 richer in sugar, which corresponds with the older statements of 

 CLAUDE BERNARD. Such a difference may, however, be caused by 

 the operative interference in the collection of the blood from the 

 hepatic vein (ABELES), and as a rule investigators nowadays do not 

 seem to agree with BERNARD'S view. During the digestion of food 

 rich in carbohydrates the blood of the portal vein may not only be 

 richer in glucose but also contain other carbohydrates (v. MERINO. 



