1888.] 



On the Coagulation of the Blood. 



283 



spontaneously coagulable, the other containing it, and therefore 

 being spontaneously coagulable. 



II. Dr. Halliburton further asserts, that whereas in the abstract 

 of the Croonian Lecture, I described a body, B-fibrinogen, in the 

 paper in Ludwig's ' Festschrift,' published shortly afterwards, this 

 body was not mentioned, or had become identical with the fibrinogen 

 of Hammarsten. This statement is totally incorrect, for on page 228 

 of Ludwig's ' Festschrift ' there will be found a paragraph headed 

 " B-fibrinogen," and on the following page this passage occurs: 

 " Man sieht also dass das Fibrinogen von Hammarsten in Plasma 

 einen Vorganger hat, welche andere Eigenschaften besitzt, und ich 

 bezeichne diese Substanz als ' B-fibrinogen.' " The differences between 

 the two bodies here referred to are precisely those mentioned in the 

 abstract of the Croonian lecture, and are shortly as follows : — 



(a.) B-fibrinogen does not clot with fibrin ferment, but it does clot 

 with leucocytes and other animal and vegetable cells. 



(b.) It clots with substances which can be obtained from these 

 animal and vegetable cells in large quantities, by extraction 

 with water. These substances I call tissue fibrinogens. 



(c.) It further clots with lecithin. 



Hammarsten's fibrinogen, in remarkable contrast with the properties 

 of this body, does not clot with leucocytes or other animal or vegetable 

 cells, nor does it clot with the substances called tissue fibrinogens 

 nor with lecithin. 



I would here add that the fibrinogen in most transudation fluids is 

 similar to Hammarsten's fibrinogen. I have clearly indicated these 

 differences in previous publications. 



III. With regard to Dr. Halliburton's remark on the relation of 

 lecithin to clotting, I may say that it not only gives rise to clotting in 

 peptone plasma and cooled plasma, but in a solution of fibrinogen 

 isolated from salt plasma and in the plasma obtained from the blood 

 after the injection of tissue fibrinogen. In discussing the experi- 

 ments on the behaviour of cooled blood towards lecithin, Dr. Halli- 

 burton does not recount the details of the experiments, and hence he 

 conveys a misleading impression of the same. It is necessary for 

 these experiments to use a finely particulate and yet thick emulsion 

 of lecithin, for the following very obvious reasons. The lecithin is 

 insoluble in the salt solution into which the blood is received, and a 

 large quantity of blood being received into a relatively small quantity 

 of the salt solution, the lecithin does not come into contact with all 

 the plasma unless a fine thick emulsion be used. 



The fact that fluids free from lecithin produce clotting, in no way 

 disproves the contention that lecithin is an essential factor in coagu- 

 lation, since every variety of fibrinogen contains lecithin. Lecithin 



VOL. xliv. z 



