264 



Dr. W. D. Halliburton. 



A and B fibrinogen are compounds of lecithin and proteid, and fibrin 

 results from the transference of the lecithin from A fibrinogen to B 

 fibrinogen. C fibrinogen is what has hitherto been called fibrinogen ; 

 A fibrinogen is a substance which may be precipitated by cooling 

 "peptone plasma," and on the removal of this substance coagulation 

 occurs with great difficulty. The precipitate produced by cold con- 

 sists of rounded bodies resembling the blood-plates in appearance. 

 He further found that other compounds of lecithin and proteid to 

 which he has extended the name of fibrinogen exist in the testis, 

 thymus, and other organs, in the fluid of lymph glands, and in the 

 stromata of red corpuscles ; these substances may be extracted from 

 the organs by water, and precipitated from the aqueous extract by 

 acetic acid, and on redissolving this in a saline solution, and injecting 

 it into the circulation of a living animal, intravascular clotting occurs 

 which results in the death of the animal. This form of fibrinogen (?) 

 that acts thus he looks upon as the precursor of A fibrinogen. From 

 these points of view the fibrin ferment and the white corpuscles are 

 looked upon as of secondary import in causing coagulation, though it 

 is admitted that fibrin ferment converts C fibrinogen into fibrin. 



In a more recent paper* these fibrinogens are somewhat differently 

 lettered ; B fibrinogen seems to have disappeared, and C fibrinogen 

 now receives that name. 



I have been carefully through all Wooldridge's papers, and I have 

 by examination of the statements made therein, and by a few test 

 experiments of my own, come to the conclusion that the theory is 

 untenable ; I will take up the chief facts upon which the theory 

 rests, one by one. 



1. TJie Influence of Lecithin in the Coagulation of the Blood. — 

 Lecithin hastens the coagulation of blood-plasma, which has been pre- 

 vented from clotting by the injection into the circulation of a certain 

 quantity of commercial peptone. f The term " peptone plasma " is a 

 convenient one to retain, though it must be remembered that it is 

 not the peptone in it that has the action in question, but the albu- 

 moses, and especially heteroalbumose. % Wooldridge§ also found by 

 receiving the blood of a dog into a thick emulsion of lecithin coagu- 

 lation occurred more quickly than when it was received into a corre- 

 sponding quantity of saline solution. 



It is upon these experiments that the theory that lecithin is the 

 essential cause of the coagulation depends. I am very little inclined 



* Ludwig's ' Festschrift,' p. 221. 



f Wooldridge, ' Jourrt. of Physiol.,' vol. 4, p. 226. 



X Pollitzer, ' Journ. of Physiol.,' vol. 7, p. 289. Pollitzer also found that these 

 proteids also delayed the coagulation of hlood after it was shed. I have found them 

 to cause a similar delav in the clotting of dilute salted plasma. 



§ ' Journ. of Physiol.,' vol. 4, p. 367. 



