318 THE BLOOD. 



gram in 100 grams of blood. The blood of the portal vein contains 

 considerably more than the blood of the arteries, being 3-4.5 times richer; 

 this, however, is disputed by BIEDL and WiNTERBERG. 1 The blood from, 

 healthy persons contains on an average 0.90 milligram per 100 cc., 

 according to WiNTERBERG. 2 The quantity of uric acid may be 0.1 p. m. 

 in bird's blood (v. SCHRODER 3 ) . Uric acid has not been detected 

 with positiveness in human blood under normal conditions, while it has 

 been found in the blood in gout, croupous pneumonia, and certain other 

 diseased conditions. Lactic acid was first found in human blood by 

 SOLOMON and then by GAGLIO, BERLINERBLAU, and IRISAWA. The 

 quantity of lactic acid may vary considerably. BERLINERBLAU found 

 0.71 p. m. as maximum. SAITO and KATSUYAMA 4 found on an average 

 0.269 p. m. in hen's blood, and after carbon-monoxide poisoning the 

 quantity increased to 1.227 p. m. 



The Composition of the Blood in Different Vascular Regions and under 



Different Conditions. 



Arterial and Venous Blood. The most striking difference between 

 these two kinds of blood is the variation in color caused by their contain- 

 ing different amounts of gas and different amounts of oxyhsemoglobin 

 and haemoglobin. The arterial blood is light red; the venous blood is 

 dark red, dichroic, 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, was 

 formerly said to be somewhat poorer in water but richer in blood-cor- 

 puscles and hemoglobin than the arterial blood; but this is denied by 

 modern investigators. According to KRUGER 5 and his pupils the quantity 

 of dry residue and hemoglobin in blood from the carotid artery and from 

 the jugular vein (in cats) is the same. ROHMANN and MUHSAM 6 could 

 not detect any difference in the quantity of fat in arterial and venous blood. 

 Blood from the Portal Vein and the Hepatic Vein. In consequence of 

 the small quantities of bile and lymph formed relatively to the large quan- 

 tity of blood circulating through the liver in a given time, we can hardly 

 .xpect to detect by chemical analysis a positive difference in the com- 

 position between the blood of the portal and hepatic veins. The state- 



1 Pfliiger's Arch., 88. 



2 Wien. klin. Wochenschr., 1897, and Zeitschr. f. klin. Med., 35. 



3 Ludwig's Festschrift, 1887. 



4 Irisawa, Zeitschr. f. physiol. Chem., 17, which also gives the older literature; Saito 

 and Katsuyama, ibid., 32. 



5 Zeitschr. f. Biologic, 26. This also gives the literature on the composition of the 

 blood in different vascular regions. 



6 Pfliiger's Archiv, 46. 



