92 PHYSIOLOGICAL CHEMISTRY. 



colorless blood-corpuscles in the coagulation. On the contrary, he 

 has observed that in crab's blood a so-called " plasmoschise" which 

 is the exit of constituents of the cells in the plasma, takes place 

 before the coagulation, and this process, he claims, stands in close 

 relationship to the coagulation of the blood. If we do not give too 

 much weight to the destruction of the leucocytes, and we admit 

 as most essential this part of SCHMIDT'S theory that the impulse to 

 the coagulation comes from the colorless blood-corpuscles, and that 

 the constituents of the same, passing into the plasma, take part in 

 the coagulation, then SCHMIDT'S theory is not disproved by the 

 investigations of the last years, but it is even supported by them. 



In opposition to the view of ALEX. SCHMIDT, who considers 

 the fibrin coagulation as an enzymotic process, WOOLDRIDGE is of 

 the opinion that the fibrin ferment is not the cause of the coagu- 

 lation, but is a product of the chemical processes taking place 

 during coagulation. WOOLDRIDGE claims, on the contrary, that 

 lecithin and proteid substances containing lecithin are of the 

 greatest importance in the coagulation. This product is obtained 

 by cooling the peptone-plasma which has been centrifugated, and 

 the substance which separates has been called by WOOLDRIDGE 

 ./4-fibrinogen. The plasma, according to WOOLDRIDGE, contains 

 in itself all qualities necessary to produce a coagulation, and the 

 form-elements are only of a secondary importance. Peptone-plasma 

 which has been centrifugated and which is entirely free from form- 

 elements, but contains the ^4-fibrinogen, coagulates on diluting 

 with water, by the passage of carbon dioxide through the liquid, or 

 after the addition of a little acetic acid, and the fibrin ferment is 

 thereby formed. WOOLDRIDGE designates as 6-fibrinogen the ordi- 

 nary fibrinogen isolated by the method suggested on page 56. This 

 fibrinogen occurs indeed in transudations, but it only occurs in the 

 peptone-plasma in very small quantities. A third fibrinogen 

 occurs in the greatest amounts in the peptone-plasma, and this is 

 the mother-substance of the (7-fibrinogen, and called i?-fibrinogen 

 by WOOLDRIDGE. The J9-fibrinogen is converted into fibrin by 

 lecithin and leucocytes from the lymphatic glands, but not by 

 fibrin ferment or blood-serum. After the previous action of serum 

 or fibrin ferment the ^-fibrinogen yields fibrin on diluting with 

 water. The one most essential for the fibrin coagulation is, ac- 



