322 DISTURBANCES OF CIRCULATION 



in diseases without leucocytosis (typhoid, malaria, nephritis), the 

 fibrin was normal in amount. Stassano and Billon^^ have, further- 

 more, shown that the amount of fibrin-ferment varies directlj^ with 

 the number of leucocytes in the blood. Kollmann^^ found an increase 

 in the fibrin of eclampsia, which Lewinski^^ could not substantiate. 

 In experimental infections of anitnals Langstein and Mayer^" found 

 a specific increase in pneumococcus sepsis, which undoubtedly bears 

 an important relation both to the characteristic fibrinous nature of 

 the alveolar exudate in pneumonia, and the striking amount of fibrin 

 found in pneumococcus pleuritis, peritonitis, etc. Mathews^^ found 

 an increase in the fibrin with all experimental suppurations. 



The coagulation time determined by different methods, in which 

 different conditions for coagulation are presented, varies from 2 to 30 

 minutes; with most methods it is 5 to 8 minutes. ^^ In general, 

 coagulability is not constantly if at all altered bj^ fever, cancer, dia- 

 betes, slight secondary anemias, or many other diseases, and in nor- 

 mal conditions it remains fairly constant. In infants the coagulation 

 time is slightly shorter than in adults. The coagulation is hastened 

 after considerable hemorrhages, in endocarditis, and perhaps in aneu- 

 rism and thrombosis; and is commonly delayed in the acute exan- 

 themata, in hemophilia, in purpura neonatorum, and occasionally in 

 some other diseases.^ There is entire lack of agreement concerning 

 the reputed acceleration of coagulation by oral administration of cal- 

 cium salts, and retardation by citrates; and the supposed thrombo- 

 plastic influence of gelatin cannot be shown consistently by direct 

 observations. In jaundice, calcium salts probably have an effect, since 

 here the cause of the deficient coagulation seems to be the fixation or 

 precipitation of the blood calcium by the bile pigments. The bile 

 salts also prevent the conversion of fibrinogen into fibrin.''^ It seems 

 probable that the measurement of the time required for coagulation to 

 take place in vitro does not exactly represent the tendency of the same 

 blood to coagulate in the body of the person from whom it is obtained; 

 for example, the injection of foreign serum has a notable effect in stop- 

 ping hemorrhages, but the coagulation time of the recipient's blood is 

 not correspondingly altered. Whipple's observation that with a low 

 fibrinogen content the blood may coagulate in normal time, and yet the 

 clots be too delicate to stop hemorrhage, explains at least part of the 

 discrepancy; and of similar signifiance is the fact that with a very 



" Compt. Rend. See. Biol., 1903 (55), 511. 



»5Cent. f. Gyniik., 1897 (21), 341. 



»« Pfliiger's Arch., 1903 (100), (ill. 



" Hofnieister's Bcitr., 1903 (5), 09. 



»« Amer. Jour. Physiol., 1899 (3), 53. 



*" Full review and bibliography by Cohen, Arch. Int. Med., 1911 (8), 084 and 

 820. 



' See Dochez (Jour. Exp. Med., 1912 (10), 093), who found some delay in 

 coagulation in pneumonia. Corroborated.by Minot and Lee, Jour. Anier. Med. 

 Assoc, 1917 (08), 645. 



