The Action of " Peptone" on Blood and Immunity thereto. 381 



pari passtt with the coagulant action arising from the intravenous injection 

 of lung extract. It is well known that the advent of asphyxia will 

 determine the appearance of thrombosis after the injection of such amounts 

 of kidney nucleoprotein as, in the presence of normal amounts of carbon 

 dioxide, tend to produce incoagulability or immunity. In like manner 

 Halliburton and Pickering (49) showed that an increase in the concentration 

 of the carbon dioxide of the blood will annul the " negative phase " 

 resulting from the injection of minimal doses of these synthesised substances 

 which have been shown to be intravascular coagulants (Pickering, 50). 



Still more significant is the correlation of all these " negative phases " 

 and temporary immunities to the factors of the speed of action and 

 concentration of the toxic substances. In this respect they are similar 

 to the " negative phases " which occur in vitro alluded to earlier in 

 this paper. 



There is a physical or physico-chemical interpretation indicated. 

 An application of the theorem of Le Chatelier (51) may provide a more 

 satisfactory explanation than is afforded by current hypotheses. 



On Experiments with perfused Livers. 



It is commonly held that perfusion of the liver affords evidence of the 

 secretion of antithrombin by that organ. Delezenne (52) and later Noli (53), 

 who had doubtful results, found that perfusion of the liver with a mixture 

 of defibrinated blood and "peptone" gave an incoagulable liquid which, 

 when added to shed blood, retarded its coagulation. Apparently these 

 workers were unaware of earlier observations of Pavloff (54), who had found 

 that the circulation of a mixture of defibrinated and normal blood through 

 a heart-lung preparation yielded a fluid which remained uncoagulated for 

 several days. "Work is now in progress which indicates that certain products 

 of autolysis may act as anticoagulants, and in view of Pavloff s experiments 

 it is superfluous to assume that Delezenne's results were due to hepatic 

 activity. Doyon (55) connected the carotid of one dog with the portal 

 vein of another, and examined the coagulation times of blood from the 

 inferior vena cava. With young fasting dogs the first perfusates coagulated 

 normally, but later samples showed delay in coagulation. With adult dogs, 

 even after fasting, no retardation of clotting was observed. It is well 

 known that the blood of embryos is resistant to clotting and these isolated 

 experiments only afford evidence of a similar phenomenon in the blood of 

 young fasting dogs. 



