THE COAGULATION OF THE BLOOD 71 



the plasma easily clots on the addition of tissue-extract. The 

 development of anti-thrombin is apparently bound up with the 

 function of the liver. If this is shunted out of the circulation, 

 peptone, on injection, is without influence on the coagulability 

 of the blood, though if only the lymphatics of the organ are 

 ligatured, peptone, as Starling and Delezenne have shown, still 

 produces its effect. The artificial perfusion of the liver, but of 

 no other organ, with a fluid containing peptone, yields an anti- 

 coagulant substance, not because this is formed directly from 

 the peptone, but from the liver-cells as a specific product of 

 reaction. A complete explanation of the effect of peptone is 

 at present not possible. It resembles the plasma of birds ? 

 except that in these animals thrombo-kinase is absent. An 

 injection of peptone into the goose yields a blood with a marked 

 amount of anti-thrombin. Such blood clots easily with kinase, 

 but with difficulty on the addition of thrombin or goose serum- 

 In this respect the effects of peptone injection are less marked 

 in birds than mammals (Fuld). 



8. The Intravenous Injection of Thrombo-Kinase 



An injection of kinase may, according to the animal and the 

 dose, yield a blood from which a kinase-plasma may be obtained 

 that clots slowly or not at all. The introduction of this sub- 

 stance, as already mentioned, may cause intra-vascular clotting, 

 but the organism, as the observations of Wooldridge, Groth, 

 and Wright have shown, undoubtedly can cope with and 

 neutralise the effects that would occur if thrombin, as such, 

 circulated in the blood. When clotting is induced, as Wright 1 

 first pointed out by experiments on animals rendered either 

 apnceic or asphyxiated, the presence of carbon dioxide in the 

 blood is one of the deciding factors. Essential differences have 

 been pointed out by Boggs between peptone- and kinase-plasma- 

 Dilution with water, addition of acid, or addition of calcium 

 chloride does not induce the latter to coagulate. When the 

 action of thrombin upon kinase-plasma is contrasted with its 

 behaviour towards peptone-plasma, it can be seen that coagula- 

 tion occurs readily in the former, but with difficulty or not at 

 all in the latter, while other experiments have shown that 



1 Journ. of Physiol, xii. 1891. 



