COAGULATION OF THE BLOOD. 303 



elements of the blood of bodies which accelerate or retard the coagula- 

 tion. According to this author the nature of these bodies is very markedly 

 different from SCHMIDT'S idea. While, according to SCHMIDT, the coagu- 

 lation accelerators are bodies soluble in alcohol, and the compound pro- 

 teins exhausted with alcohol act only retardingly on coagulation, LILIEN- 

 FELD states that the substance which acts acceleratingly and retardingly 

 on coagulation are contained in a nucleoprotein, namely, nucleohistone. 

 Nucleohistone readily splits into leuconuclein and hist one, the first of 

 which acts as a coagulation-excitant, while the other, introduced into 

 the blood-vascular system, either intravascular or extravascular, robs 

 the blood of its property of coagulating. Introduced into the circulatory 

 system the nucleohistone splits into its two components. It therefore 

 causes extensive coagulation on one side and makes the remainder of 

 the blood uncoagulable on the other. This theory as well as that of 

 SCHMIDT is not based upon sufficiently demonstrated facts. 



BRUCKE showed long ago that fibrin left an ash containing calcium 

 phosphate. The fact that calcium salts may facilitate or even cause a 

 coagulation in liquids poor in ferment has been known for several years 

 through the researches of HAMMARSTEN, GREEN, RINGER and SAINS- 

 BURY. The necessity of the lime salts for the coagulation of blood and 

 plasma was first shown positively by the important investigations of 

 ARTHUS and PAGES. Recent investigations of SABBATANI 1 have also 

 shown the importance of calcium salts or the free calcium ions for 

 coagulation without explaining the mode of their action. 



According to the generally accepted view of ARTHUS and PAGES the soluble 

 lime salts precipitable by oxalate are necessary requisites for the fermentive 

 transformation of fibrinogen, because thrombin remains inactive in the absence 

 of soluble lime salts. This view is untenable, as shown by the researches of 

 ALEX. SCHMIDT, PEKELHARING, and HAMMARSTEN. 2 Thrombin acts as well in 

 the absence as in the presence of precipitable lime salts. 



LILIENFELD'S theory that the leuconuclein splits off a protein substance, 

 thrombosin, from the fibrinogen, and that this thrombosin forms an insoluble com- 

 pound with the lime present, producing thrombosin lime (fibrin), which separates, 

 is incorrect according to HAMMARSTEN, SCHAFER, and CRAMER. 3 LILIENFELD'S 

 thrombosin is nothing but fibrinogen which is precipitated by a lime salt from a 

 salt-poor or salt-free solution. 



According to PEKELHARING 4 thrombin is the lime compound of 



1 Hammarsten, Nova Acta reg. Soc. Sclent. Upsal. (3), 10, 1879; Green, Journ. oj 

 Physiol., 8; Ringer and Sainsbury, ibid., 11 and 12; Arthus et Pages and Arthus, 

 see footnote 6, p. 243; Hammarsten, Zeitschr. f. physiol. Chem., 22; Sabbatani, 

 cited, Centralbl. f. Physiol., 16, 665. 



2 Hammarsten, Zeitschr. f. physiol. Chem., 22, where the other investigators are 

 cited. 



3 Hammarsten, 1. c.; Schafer, Journ. of Physiol., 17; Cramer. Zeitschr. f. physiol. 

 Chem., 23. 



4 See footnote 3, p. 248, and especially Virchow's Festschrift, 1, 1891. 



