380 



CHEMISTRY OF THE PROTEIDS 



CHAP. 



Fano. 1 That the protamins act in a similar manner has been shown 

 by Thompson. 2 The nucleo-histone of the thymus (Lilienf eld 3 ) as 

 well as other albuminous substances, and derivatives from the most 

 diverse "organs all act as anti-coagulators. 



Coagulation-temperature. The coagulation-temperature of fibrino- 

 gen, according to Fredericq, 4 is 56. It is of special interest that he 

 obtained three distinct coagulation-temperatures, at 56, 67, and 75, 

 belonging to the three distinct albumins in the case of plasma ; while 

 with serum no sharp demarcation occurs between 64 and 75. The 

 reason for this behaviour is that fibrinogen gives rise to fibrin- 

 globulin coagulating at 6 4, and that certain cell-albumins are liberated 

 by the disintegration of blood-corpuscles during clotting. 



Fredericq 5 found in blood-plasma 0'4299 per cent fibrinogen, 

 while Reye 6 obtained 0*3479 per cent. Fibrinogen occurs also in 

 lymph and in pathological transudations. Fibrinogen has not been 

 prepared in a crystalline form. 7 Analysis gives the following figures : 



The dissociation-products are given on p. 71, No. 9. 



Sulphur does not only occur as cystin, according to Morner. 10 



Salts of fibrinogen and halogen compounds are not known. 



Fibrinogen shows the general characteristics of the globulins ; it 

 is insoluble in water, but soluble in salt-solutions. It is further 

 soluble in dilute alkalies and in the alkali-carbonates ; it is, however, 

 precipitated by the addition of very minute traces of neutral salts, 

 and passes, again into solution on the addition of further quantities of 

 salt. 8 It is also precipitated by dilution with water, by dialysis, by 

 the passage of a stream of carbon-dioxide, and by acetic acid. Pre- 

 cipitation is, however, as in the case of globulins, not a complete one. 



1 Fano, Archiv.f. (Anat. u.) Physiol. 1881, p. 277. 



2 W. H. Thompson, Zeitschr. f. physiol. Chem. 29. 1 (1899). 



3 L. Lilienfeld, ibid. 20. 89 (1894). 



4 L. Fredericq, Bull, de I'Acad. royale de Belgique, 2nd ser. 64. 7 (1877) (reprint) ; 

 Ann. de Soc. de Medecine de Gant, 1877 (reprint). 



5 L. Fredericq, Bull, de I'Acad. royale de Belgique, 2nd ser. 64. 7 (1877) (reprint). 



6 W. Reye, Dissertation, Strassburg, 1898. 



7 S. Dziergowski, Zeitschr. f. physiol. Chem. 28. 65 (1899). 



8 0. Hammarsten, Pftuger's Arch.f. d. ges. Physiol. 22. 431 (1880). 



9 C. D. Cramer, Zeitschr. f. physiol. Chem. 23. 74 (1897). 

 10 K. A. H. Morner, ibid. 34. 207 (1901). 



