i 7 8 THE BLOOD. 
although it speedily occurs on further addition of lime or on passing 
CO.> Wright 1 assumes that the nucleo-proteid acting as a weak acid 
has ousted C0 2 from the hases of the plasma, and that the action of CO., 
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 
< >bscurity. 
Influence of the liver and lungs upon blood coagulability. — It was shown by 
Pawlow 2 that if blood be allowed to circulate 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 JSTewell 
.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. Delezenne 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 
Hedon 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 has 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 temporaril}' 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. Toth. ami Baeteriol., Edin. and London, 1893, vol. i. p. 434. 
2 Arch.f. Physiol., Leipzig, 1887, S. 458. 
3 Quoted by Gad, Verhomdl. d. Berl. phys. Gesellsch., Arch. f. Physiol., Leipzig, 1887, 
S. 584. 
4 Centralbl.f. Physiol., Leipzig u. VVien, 1888, S. 261. 
5 Compl. rend. Acad. d. sc, Paris, 11 Mai, 1896, p. 1072. 
6 Arch, de physiol. norm, ctpath., Paris, 1895, p. 711. " Ibid. p. 245. 
8 Ibid., 1896, p. 159. 
9 Compt. rend. Soc. de. biol.. Paris, 1S96, p. 633. 
