160 THE BLOOD. 



been perfused through the still living kidneys or lungs, or through the 

 muscles of the lower limb, especially if inosit or glycogen or dextrose 

 be added to the blood used for perfusion (Gaglio, Berlinerblau). It is 

 also increased by intravenous injection of dextrose in blood circulating 

 normally through the body. It appears to enter into combination with 

 sodium hydrate, driving out CO^ 1 



Non-proteid nitrogenous constituents of plasma. The most im- 

 portant of these are urea 2 (0'02-0'05 per cent.), kreatin, kreatinine, 3 

 and uric acid, 4 and occasionally hippuric acid. 5 Xanthine and hypo- 

 xanthine are stated to be also present. 6 Grehant and Quinquand found 

 the amount of urea in blood drawn from the splenic, portal, and hepatic 

 veins to be slightly greater than in that taken from the carotid. 7 

 Lecithin occurs in small amount in. plasma. 8 According to Marino- 

 Zucco, neurine and glycero-phosphoric acid are also present in traces in 

 the free state. There has also been described as a constant constituent, 

 jecorin 9 a substance which reduces Fehling's solution, but is soluble 

 in ether and is not fermentable. It is stated to occur in considerably 

 larger amount in venous than in arterial blood. 10 



Ferments. Three ferments have been described as occurring in blood, 

 namely 



1. A diastatic ferment, producing the conversion of amyloids to sugar. 



2. A glycolytic ferment, producing the disappearance of sugar. 



3. A fat-splitting ferment (lipase). 11 



4. A fibrin ferment (thrombin), or its precursor (prothrombin), pro- 

 ducing the formation of fibrin from fibrinogen. The last will be con- 

 sidered in connection with coagulation. 



Diastatic action. A ferment action, converting starch into dextrin 

 and maltose, and ultimately into dextrose, has been obtained with 

 blood and lymph by Eohmann 12 and Bial, 13 and also by Hamburger, 14 by 



1 Vaughan Harley, Arch. f. Physiol., Leipzig, 1894, S. 451. 



2 Simon, Arch. f. Anat. u. Physiol. t Leipzig, 1841, S. 454 ; I. Munk, Arch. f. d. ges. 

 Physiol., Bonn, 1875, Bd. xi. S. 105; Schroder, Arch. f. exper. Path. u. Pharmakol., 

 Leipzig, 1882, Bd. xv. S. 364 ; and 1885, Bd. xix. S. 373. Picard (Jpurn. de I'anat. et 

 physiol. etc., Paris, 1881, p. 530) found the percentage of urea rather higher than this in 

 the dog (0-09 to 0-13). 



3 Yerdeil and Marcet found both kreatin and kreatinine (Journ. de pharm. et chim., 

 Paris, 1851, tome xx. p. 89) ; Voit (Ztschr. f. Biol., Miinchen, 1868, S. 93) could find no 

 kreatinine ; but Colls (Journ. Physiol., Cambridge and London, 1896, vol. xx. p. 107) 

 obtained a small but definite quantity. 



4 Scherer and Strecker, quoted by Hoppe-Seyler ("Physiol. Chem."); Garrod, Med.- 

 Chir. Trans., London, 1848, vol. xxxv. p. 83, and 1854, vol. xxxvii. p. 49. See also 

 "Nature and Treatment of Gout," 1861 ; Abeles, Med. Jahrb., Wien, 1887, S. 479. On 

 the other hand, v. Jaksch (Ztschr. f. Heilk., 1890, Bd. xi. S. 415) could find no uric 

 acid in the blood of healthy individuals (nine cases). 



5 Verdeiland Goldfuss, Compt. rend. Soc. debiol., Paris, 1850, tomeii. p. 79. Meissnerand 

 Shepard (" Untersuch. ii. d. Ensteh. d. Hippurs.," Hannover, 1866) were unable to find it. 



6 Halliburton, "Chem. Physiol.," p. 251. 



7 Journ. de I'anat. et physiol. etc., Paris, 1884, p. 317. 



8 Hoppe-Seyler, Med. Chem. Untersuch., Berlin, 1869, S. 551. 



9 Baldi, Arch. f. Physiol., Leipzig, 1887, Suppl. Heft, S. 100; Henriques, Ztschr. f. 

 physiol. Chem., Strassburg, Bd. xxiii. S. 244. 



10 Jacobsen, Centralbl. f. Physiol., Leipzig u. Wien, 1892, S. 368. 



11 Hanriot, Compt. rend. Soc. de biol., Paris, 1896, p. 925. 



12 Arch.f. d. ges. Physiol., Bonn, 1892, Bd. lii. S. 157. 



13 Ibid., 1892, Bd. lii. S. 137; and Bd. liii. S. 156; Rohmann and Bial, Arch. f. 

 d. ges. Physiol., Bonn, 1893, Bd. liv. S. 72 ; Bd. Iv. S. 469. According to Le'pine and 

 Barral (Compt. rend. Acad. d. sc., Paris, 1893, tome cxiii., pp. 118, 729, 1014, and cxv. 

 p. 304) sugar may be formed in blood on standing, at the expense of added peptone, as 

 well as starch or glycogen ; but this was not confirmed by Bial. 



u lbid., 1895, Bd. Ix. S. 543. 



