THE COAGULATION OF THE BLOOD 7 
the plasma easily clots on the addition of tissue-extract. The 
development of antithrombin 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. Tue 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! 
first pointed out by experiments on animals rendered either 
apneeic 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. 
