1 78 THE BLOOD. 



although it speedily occurs on further addition of lime or on passing 

 C0 2 . Wright l assumes that the nucleo-proteid acting as a weak acid 

 has ousted C0 from the bases of the plasma, and that the action of C0 2 

 is to set the nucleo-proteid free again. But this would not account for 

 the effect of addition of calcium chloride. It may, on the other hand, be 

 that the lime which is present in the plasma is unable to act upon the 

 nucleo-proteid also present, owing to the former having entered into some 

 combination from which it is set free by C0 2 . It must be admitted 

 that the subject is still, in spite of much research, enveloped largely in 

 obscurity. 



Influence of the liver and lungs upon blood coagulability. It was shown by 

 Pawlow 2 that if blood be allowed to emulate through the heart and lungs 

 only, and be cut off from the rest of the body, it gradually loses its 

 coagulability, and the same observation was made independently by Jewell 

 Martin. 3 Bohr 4 obtained a similar result, on preventing the blood from 

 reaching the portal circulation by occluding the thoracic aorta. The blood 

 lost its coagulability in a quarter of an hour, nor was it restored for twenty-four 

 hours after readmission to the abdominal viscera. This was in the dog. In a 

 rabbit, ligature of the coeliac axis and mesenteric arteries produced a similar 

 but rather less pronounced effect. Delezemie has shown that artificial 

 perfusion of " peptone-blood " through the liver restores its coagulability, but 

 that other organs do not produce the same result. 5 



Gley and Pachon 6 find, in confirmation of Contejean, 7 that every cause 

 which diminishes or suppresses the functional activity of the liver diminishes 

 or suspends the anti-coagulating action of " peptone." They thus explain the 

 experiments of Contejean, who noticed that after extirpation of the coeliac 

 ganglia the action of " peptone " is not obtained. 8 



H6don and Delezenne 9 also found that after the establishment of an Eck's 

 fistula (communication between portal vein and vena cava) in the dog, and the 

 subsequent removal of the liver, injection of " peptone," although it produces 

 a great fall of blood pressure, no longer removes the coagulability of the blood. 

 These experiments appear to show that the liver lias a special function in 

 connection with the maintenance of the coagulability of the blood, and that in 

 passing through the lungs an effect of an opposite character is produced, but 

 in what way exactly these organs exert their influence has not as yet been 

 ascertained. 



Blood or plasma can be temporarily made uncoagulable in the living vessels 

 by removing the fibrin. Dastre found that, if a large quantity of blood be 

 drawn from an animal, and this be whipped and filtered and returned to the 

 blood vessels, and the process repeated two or three times, all the fibrin can 

 be temporarily removed ; and it is only gradually that the blood resumes its 

 coagulability, which is not completely restored until the lapse of some 

 hours. 



Conclusions regarding the causes of coagulation. At least three 

 factors appear necessary to effect the formation of fibrin, namely, 



1 Journ. Path, and Bacterial., Edin. and London, 1893, vol. i. p. 434. 



2 Arch. f. PhysioL, Leipzig, 1887, S. 458. 



3 Quoted by Gad, VerhandL d. Berl. phys. Gesellsch., Arch. f. PhysioL, Leipzig, 1887, 

 S. 584. 



4 CentralU.f. PhysioL, Leipzig u. Wien, 1888, S. 261. 



5 Compt. rend. Acad. d. sc., Paris, 11 Mai, 1896, p. 1072. 



6 Arch, dephysiol. norm, etpath., Paris, 1895, p. 711. 7 Ibid. p. 245. 



8 Ibid., 1896, p. 159. 



9 Compt. rend. Soc. de. MoL, Paris, 1896, p. 633. 



