THE COAGULATION OF THE BLOOD. 369 



(nucleo-proteid in nature, prothrombin by name) which is not 

 fibrin-ferment, but which by the action of soluble lime salts 

 becomes converted into another substance (also essentially 

 nucleo-proteid in nature, but thromb'n by name) is easily 

 confirmed. This second substance is a powerful accelerator 

 of the coagulation process, and is in fact fibrin-ferment. 



Lilienfeld's facts and theories are wrong throughout. 

 This worker stated that if he took a solution of fibrinogen, 

 and added to it some acetic acid, he obtained a precipitate 

 of a new material which he called thrombosin ; if he then 

 added calcium salts to a solution of thrombosin he obtained 

 a formation of fibrin. Thrombosin may also be precipi- 

 tated from a fibrinogen solution by nucleic acid, and this is 

 what he considered to occur in actual coagulation ; the 

 nucleic acid of the nucleo-proteid in the blood first separates 

 thrombosin from fibrinogen, and then the thrombosin is 

 precipitated as fibrin by calcium. 



It has already been stated that Schafer could not con- 

 firm this, and no more can Hammarsten. The so-called 

 thrombosin is no new substance, it is simply fibrinogen 

 which is partially precipitable by the acids just mentioned. 

 When it is dissolved in saline solution and a soluble calcium 

 salt added there is neither coagulation nor precipitation 

 if fibrin-ferment is absent, though if fibrin-ferment is present, 

 even though soluble lime salts are absent, fibrin is formed in 

 the usual way. 



It may be added that Lilienfeld is equally wrong when 

 he distinguishes between nucleo-proteid and fibrin-ferment. 

 Fibrin-ferment is not a globulin ; it is a nucleo-proteid. It 

 is not the result of fibrin formation as Lilienfeld states, 

 but all the facts at present at our disposal point to it as the 

 main cause of the transformation of fibrinogen into fibrin. 



Underlying the theories of Arthus, Pekelharing and 

 Lilienfeld there is one fallacy common to all. All look 

 upon fibrin as a calcium compound of fibrinogen or of some 

 derivative of fibrinogen. Hammarsten states this is not the 

 case. Both fibrin and fibrinogen contain calcium, but there 

 is the same amount of that element in each. 



W. D. Halliburton. 

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